CWE-73
AllowedExternal Control of File Name or Path
Abstraction: Base · Status: Draft
The product allows user input to control or influence paths or file names that are used in filesystem operations.
1200 vulnerabilities reference this CWE, most recent first.
GHSA-657C-G7QC-R9J2
Vulnerability from github – Published: 2026-09-17 14:58 – Updated: 2026-09-17 14:58Impact
An OpenAPI or AsyncAPI description could make the split command write
files outside the chosen output directory, on the machine of anyone who runs
split against it. The write is constrained rather than a free file-write
primitive: component data is emitted only as YAML/JSON, and code-sample files are
named after the HTTP method, so an attacker can place or overwrite files at an
unintended path but has limited control over their name and contents.
Patches
Fixed in @redocly/cli v2.33.2.
Workarounds
Do not run the split command on API descriptions from untrusted or unreviewed sources.
To detect an exploit attempt, inspect the description's component names and
x-codeSamples lang values for a literal ../ — neither legitimately contains
path segments.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@redocly/cli"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.34.17"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "@redocly/cli"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0"
},
{
"fixed": "2.33.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-63225"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-73"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-17T14:58:50Z",
"nvd_published_at": "2026-09-16T19:17:24Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nAn OpenAPI or AsyncAPI description could make the `split` command write\nfiles outside the chosen output directory, on the machine of anyone who runs\n`split` against it. The write is constrained rather than a free file-write\nprimitive: component data is emitted only as YAML/JSON, and code-sample files are\nnamed after the HTTP method, so an attacker can place or overwrite files at an\nunintended path but has limited control over their name and contents.\n\n### Patches\n\nFixed in `@redocly/cli` v2.33.2.\n\n### Workarounds\n\nDo not run the `split` command on API descriptions from untrusted or unreviewed sources.\n\nTo detect an exploit attempt, inspect the description\u0027s component names and\n`x-codeSamples` `lang` values for a literal `../` \u2014 neither legitimately contains\npath segments.",
"id": "GHSA-657c-g7qc-r9j2",
"modified": "2026-09-17T14:58:50Z",
"published": "2026-09-17T14:58:50Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/security/advisories/GHSA-657c-g7qc-r9j2"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63225"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/pull/2891"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/pull/2923"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/commit/26a0f299fae0b3bb7bd513043d2f1e90e69f79ee"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/commit/504120419a72b5c684471478337ee3b45d8bfad3"
},
{
"type": "PACKAGE",
"url": "https://github.com/Redocly/redocly-cli"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/releases/tag/@redocly/cli@1.34.17"
},
{
"type": "WEB",
"url": "https://github.com/Redocly/redocly-cli/releases/tag/@redocly/cli@2.33.2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "Redocly CLI: Path traversal when using `split` command"
}
GHSA-65H7-6WW6-HHQJ
Vulnerability from github – Published: 2024-03-15 18:30 – Updated: 2024-03-15 18:30IBM Sterling Secure Proxy 6.0.3 and 6.1.0 could allow an attacker to overwrite a log message under specific conditions. IBM X-Force ID: 270598.
{
"affected": [],
"aliases": [
"CVE-2023-47147"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-03-15T16:15:08Z",
"severity": "MODERATE"
},
"details": "IBM Sterling Secure Proxy 6.0.3 and 6.1.0 could allow an attacker to overwrite a log message under specific conditions. IBM X-Force ID: 270598.",
"id": "GHSA-65h7-6ww6-hhqj",
"modified": "2024-03-15T18:30:36Z",
"published": "2024-03-15T18:30:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-47147"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/270598"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/7142038"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-67XF-JWPX-5M9Q
Vulnerability from github – Published: 2026-09-04 12:31 – Updated: 2026-09-04 12:31Grav versions before 1.10.55 contain a path traversal vulnerability in the admin plugin's Save As action that fails to validate the language code parameter. An authenticated admin user with admin.pages.create permission can supply directory traversal sequences in the lang POST field to write arbitrary .md files outside the pages directory with attacker-controlled content.
{
"affected": [],
"aliases": [
"CVE-2026-85603"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T12:17:24Z",
"severity": "HIGH"
},
"details": "Grav versions before 1.10.55 contain a path traversal vulnerability in the admin plugin\u0027s Save As action that fails to validate the language code parameter. An authenticated admin user with admin.pages.create permission can supply directory traversal sequences in the lang POST field to write arbitrary .md files outside the pages directory with attacker-controlled content.",
"id": "GHSA-67xf-jwpx-5m9q",
"modified": "2026-09-04T12:31:01Z",
"published": "2026-09-04T12:31:01Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/getgrav/grav/security/advisories/GHSA-h9g9-73c3-23c9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85603"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/grav-admin-plugin-path-traversal-via-save-as-language-code"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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-68R5-9HPG-7QW9
Vulnerability from github – Published: 2026-07-24 21:46 – Updated: 2026-07-24 21:46The DSMLv2 SOAP gateway (opendj-dsml-servlet) in OpenIdentityPlatform OpenDJ through 5.1.1 dereferences attacker-supplied xsd:anyURI values server-side without a scheme allowlist, egress filtering, or a size cap, and is reachable without authentication by default. A remote unauthenticated attacker can submit a DSML add/modify request whose value is a URI to (1) perform server-side request forgery against internal services and the cloud metadata endpoint (SSRF), (2) read local files via file: URIs, and (3) exhaust memory through an unbounded response read (DoS). Fixed in 5.1.2: anyURI dereferencing is disabled by default; when enabled it is limited to an http/https allowlist, rejects loopback/link-local/private/reserved targets, refuses HTTP redirects, and caps the bytes read. The gateway also now requires container-managed authentication by default.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.1.1"
},
"package": {
"ecosystem": "Maven",
"name": "org.openidentityplatform.opendj:opendj-dsml-servlet"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.1.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-73",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-24T21:46:06Z",
"nvd_published_at": null,
"severity": "CRITICAL"
},
"details": "The DSMLv2 SOAP gateway (opendj-dsml-servlet) in OpenIdentityPlatform OpenDJ through 5.1.1 dereferences attacker-supplied xsd:anyURI values server-side without a scheme allowlist, egress filtering, or a size cap, and is reachable without authentication by default. A remote unauthenticated attacker can submit a DSML add/modify request whose value is a URI to (1) perform server-side request forgery against internal services and the cloud metadata endpoint (SSRF), (2) read local files via file: URIs, and (3) exhaust memory through an unbounded response read (DoS). Fixed in 5.1.2: anyURI dereferencing is disabled by default; when enabled it is limited to an http/https allowlist, rejects loopback/link-local/private/reserved targets, refuses HTTP redirects, and caps the bytes read. The gateway also now requires container-managed authentication by default.",
"id": "GHSA-68r5-9hpg-7qw9",
"modified": "2026-07-24T21:46:06Z",
"published": "2026-07-24T21:46:06Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/OpenIdentityPlatform/OpenDJ/security/advisories/GHSA-68r5-9hpg-7qw9"
},
{
"type": "WEB",
"url": "https://github.com/OpenIdentityPlatform/OpenDJ/commit/131e8576dcf3613f944c3e02527959bbf52370c3"
},
{
"type": "PACKAGE",
"url": "https://github.com/OpenIdentityPlatform/OpenDJ"
},
{
"type": "WEB",
"url": "https://github.com/OpenIdentityPlatform/OpenDJ/releases/tag/5.1.2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H",
"type": "CVSS_V3"
}
],
"summary": "OpenDJ unauthenticated SSRF, local file read and unbounded-read DoS in the DSMLv2 gateway"
}
GHSA-69C5-XXXM-R666
Vulnerability from github – Published: 2026-01-07 12:31 – Updated: 2026-01-07 12:31The EmailKit plugin for WordPress is vulnerable to Arbitrary File Read via Path Traversal in all versions up to, and including, 1.6.1. This is due to missing path validation in the create_template REST API endpoint where user-controlled input from the emailkit-editor-template parameter is passed directly to file_get_contents() without sanitization. This makes it possible for authenticated attackers with Author-level permissions or higher to read arbitrary files on the server, including sensitive configuration files like /etc/passwd and wp-config.php, via the REST API. The file contents are stored in post meta and can be exfiltrated through MetForm's email confirmation feature.
{
"affected": [],
"aliases": [
"CVE-2025-14059"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-07T12:16:51Z",
"severity": "MODERATE"
},
"details": "The EmailKit plugin for WordPress is vulnerable to Arbitrary File Read via Path Traversal in all versions up to, and including, 1.6.1. This is due to missing path validation in the create_template REST API endpoint where user-controlled input from the emailkit-editor-template parameter is passed directly to file_get_contents() without sanitization. This makes it possible for authenticated attackers with Author-level permissions or higher to read arbitrary files on the server, including sensitive configuration files like /etc/passwd and wp-config.php, via the REST API. The file contents are stored in post meta and can be exfiltrated through MetForm\u0027s email confirmation feature.",
"id": "GHSA-69c5-xxxm-r666",
"modified": "2026-01-07T12:31:21Z",
"published": "2026-01-07T12:31:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-14059"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/trunk/includes/Admin/Api/CheckForm.php#L163"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/changeset?sfp_email=\u0026sfph_mail=\u0026reponame=\u0026new=3419280%40emailkit%2Ftrunk\u0026old=3373383%40emailkit%2Ftrunk\u0026sfp_email=\u0026sfph_mail=#file1"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/91ebe8cb-99ec-4380-a77e-17e17144a17e?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-69P7-7Q3J-7GHQ
Vulnerability from github – Published: 2026-09-07 09:31 – Updated: 2026-09-07 09:31The Windows interactive service in OpenVPN 2.4.0 through 2.6.22 allows local authenticated users to bypass the trusted configuration directory constraint via incorrect file path validation
{
"affected": [],
"aliases": [
"CVE-2026-81830"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-07T08:17:13Z",
"severity": "MODERATE"
},
"details": "The Windows interactive service in OpenVPN 2.4.0 through 2.6.22 allows local authenticated users to bypass the trusted configuration directory constraint via incorrect file path validation",
"id": "GHSA-69p7-7q3j-7ghq",
"modified": "2026-09-07T09:31:39Z",
"published": "2026-09-07T09:31:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81830"
},
{
"type": "WEB",
"url": "https://community.openvpn.net/Security%20Announcements/CVE-2026-81830"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:H/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-69RX-5VQ2-C562
Vulnerability from github – Published: 2026-08-06 09:30 – Updated: 2026-08-06 09:30A weakness has been identified in TinyAGI 0.0.20. This issue affects the function collectFiles of the file packages/core/src/response.ts of the component Message API Endpoint. This manipulation causes file inclusion. The attack can be initiated remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
{
"affected": [],
"aliases": [
"CVE-2026-19009"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-06T08:16:30Z",
"severity": "MODERATE"
},
"details": "A weakness has been identified in TinyAGI 0.0.20. This issue affects the function collectFiles of the file packages/core/src/response.ts of the component Message API Endpoint. This manipulation causes file inclusion. The attack can be initiated remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.",
"id": "GHSA-69rx-5vq2-c562",
"modified": "2026-08-06T09:30:31Z",
"published": "2026-08-06T09:30:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19009"
},
{
"type": "WEB",
"url": "https://github.com/TinyAGI/tinyagi/issues/282"
},
{
"type": "WEB",
"url": "https://github.com/TinyAGI/tinyagi"
},
{
"type": "WEB",
"url": "https://vuldb.com/cve/CVE-2026-19009"
},
{
"type": "WEB",
"url": "https://vuldb.com/submit/862672"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/386402"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/386402/cti"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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-6CQX-9V42-Q8F8
Vulnerability from github – Published: 2023-09-05 18:30 – Updated: 2024-04-04 07:29A file write vulnerability exists in the OAS Engine configuration functionality of Open Automation Software OAS Platform v18.00.0072. A specially crafted series of network requests can lead to arbitrary file creation or overwrite. An attacker can send a sequence of requests to trigger this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2023-32615"
],
"database_specific": {
"cwe_ids": [
"CWE-610",
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-09-05T17:15:08Z",
"severity": "HIGH"
},
"details": "A file write vulnerability exists in the OAS Engine configuration functionality of Open Automation Software OAS Platform v18.00.0072. A specially crafted series of network requests can lead to arbitrary file creation or overwrite. An attacker can send a sequence of requests to trigger this vulnerability.",
"id": "GHSA-6cqx-9v42-q8f8",
"modified": "2024-04-04T07:29:10Z",
"published": "2023-09-05T18:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-32615"
},
{
"type": "WEB",
"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2023-1771"
},
{
"type": "WEB",
"url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2023-1771"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6FF3-GQC7-RP56
Vulnerability from github – Published: 2024-05-14 18:30 – Updated: 2025-02-20 18:31A vulnerability was found in Campcodes Online Laundry Management System 1.0 and classified as problematic. This issue affects some unknown processing of the file /index.php. The manipulation of the argument page leads to file inclusion. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-263939.
{
"affected": [],
"aliases": [
"CVE-2024-4818"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-14T15:45:10Z",
"severity": "MODERATE"
},
"details": "A vulnerability was found in Campcodes Online Laundry Management System 1.0 and classified as problematic. This issue affects some unknown processing of the file /index.php. The manipulation of the argument page leads to file inclusion. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-263939.",
"id": "GHSA-6ff3-gqc7-rp56",
"modified": "2025-02-20T18:31:15Z",
"published": "2024-05-14T18:30:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4818"
},
{
"type": "WEB",
"url": "https://github.com/yylmm/CVE/blob/main/Online%20Laundry%20Management%20System/LFI.md"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.263939"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.263939"
},
{
"type": "WEB",
"url": "https://vuldb.com/?submit.333057"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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-6J79-XV7W-8G6F
Vulnerability from github – Published: 2024-01-09 18:30 – Updated: 2024-01-09 18:30Windows HTML Platforms Security Feature Bypass Vulnerability
{
"affected": [],
"aliases": [
"CVE-2024-20652"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-09T18:15:47Z",
"severity": "HIGH"
},
"details": "Windows HTML Platforms Security Feature Bypass Vulnerability",
"id": "GHSA-6j79-xv7w-8g6f",
"modified": "2024-01-09T18:30:28Z",
"published": "2024-01-09T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-20652"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-20652"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation
When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap provide this capability.
Mitigation
- Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory.
- Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
Mitigation
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-5.1
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 validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.
- Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would be removed from the original string, but the remaining characters would still form the "../" string.
Mitigation
Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59).
Mitigation
Use OS-level permissions and run as a low-privileged user to limit the scope of any successful attack.
Mitigation
If you are using PHP, configure your application so that it does not use register_globals. During implementation, develop your 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.
Mitigation
Use tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session. These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.
CAPEC-13: Subverting Environment Variable Values
The adversary directly or indirectly modifies environment variables used by or controlling the target software. The adversary's goal is to cause the target software to deviate from its expected operation in a manner that benefits the adversary.
CAPEC-267: Leverage Alternate Encoding
An adversary leverages the possibility to encode potentially harmful input or content used by applications such that the applications are ineffective at validating this encoding standard.
CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic
This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
CAPEC-72: URL Encoding
This attack targets the encoding of the URL. An adversary can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL.
CAPEC-76: Manipulating Web Input to File System Calls
An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
CAPEC-78: Using Escaped Slashes in Alternate Encoding
This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
CAPEC-79: Using Slashes in Alternate Encoding
This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic
This attack is a specific variation on leveraging alternate encodings to bypass validation logic. This attack leverages the possibility to encode potentially harmful input in UTF-8 and submit it to applications not expecting or effective at validating this encoding standard making input filtering difficult. UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. Legal UTF-8 characters are one to four bytes long. However, early version of the UTF-8 specification got some entries wrong (in some cases it permitted overlong characters). UTF-8 encoders are supposed to use the "shortest possible" encoding, but naive decoders may accept encodings that are longer than necessary. According to the RFC 3629, a particularly subtle form of this attack can be carried out against a parser which performs security-critical validity checks against the UTF-8 encoded form of its input, but interprets certain illegal octet sequences as characters.