CWE-434
AllowedUnrestricted Upload of File with Dangerous Type
Abstraction: Base · Status: Draft
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
6030 vulnerabilities reference this CWE, most recent first.
GHSA-CFHR-JJFR-C8C6
Vulnerability from github – Published: 2025-08-21 12:31 – Updated: 2025-08-21 12:31A security vulnerability has been detected in Emlog Pro up to 2.5.18. This affects an unknown function of the file /admin/blogger.php?action=update_avatar. Such manipulation of the argument image leads to unrestricted upload. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
{
"affected": [],
"aliases": [
"CVE-2025-9296"
],
"database_specific": {
"cwe_ids": [
"CWE-284",
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-21T12:15:29Z",
"severity": "MODERATE"
},
"details": "A security vulnerability has been detected in Emlog Pro up to 2.5.18. This affects an unknown function of the file /admin/blogger.php?action=update_avatar. Such manipulation of the argument image leads to unrestricted upload. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.",
"id": "GHSA-cfhr-jjfr-c8c6",
"modified": "2025-08-21T12:31:42Z",
"published": "2025-08-21T12:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-9296"
},
{
"type": "WEB",
"url": "https://github.com/lan041221/cvec/issues/8"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.320901"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.320901"
},
{
"type": "WEB",
"url": "https://vuldb.com/?submit.631923"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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-CFJ8-9637-66C4
Vulnerability from github – Published: 2025-09-29 21:30 – Updated: 2025-09-29 21:30Medical Informatics Engineering Enterprise Health allows authenticated users to upload arbitrary files. The impact of this behavior depends on how files are accessed. This issue is fixed as of 2025-04-08.
{
"affected": [],
"aliases": [
"CVE-2025-35032"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-29T20:15:32Z",
"severity": "MODERATE"
},
"details": "Medical Informatics Engineering Enterprise Health allows authenticated users to upload arbitrary files. The impact of this behavior depends on how files are accessed. This issue is fixed as of 2025-04-08.",
"id": "GHSA-cfj8-9637-66c4",
"modified": "2025-09-29T21:30:26Z",
"published": "2025-09-29T21:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-35032"
},
{
"type": "WEB",
"url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-25-272-01.json"
},
{
"type": "WEB",
"url": "https://www.cve.org/CVERecord?id=CVE-2025-35032"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H/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-CFPX-6J59-HGGC
Vulnerability from github – Published: 2025-10-28 03:30 – Updated: 2025-10-28 03:30A vulnerability was detected in MaxSite CMS up to 109. This vulnerability affects unknown code of the file application/maxsite/admin/plugins/auto_post/uploads-require-maxsite.php of the component HTTP Header Handler. Performing manipulation of the argument X-Requested-FileName/X-Requested-FileUpDir results in unrestricted upload. Remote exploitation of the attack is possible. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
{
"affected": [],
"aliases": [
"CVE-2025-12346"
],
"database_specific": {
"cwe_ids": [
"CWE-284",
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-28T03:15:33Z",
"severity": "MODERATE"
},
"details": "A vulnerability was detected in MaxSite CMS up to 109. This vulnerability affects unknown code of the file application/maxsite/admin/plugins/auto_post/uploads-require-maxsite.php of the component HTTP Header Handler. Performing manipulation of the argument X-Requested-FileName/X-Requested-FileUpDir results in unrestricted upload. Remote exploitation of the attack is possible. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.",
"id": "GHSA-cfpx-6j59-hggc",
"modified": "2025-10-28T03:30:19Z",
"published": "2025-10-28T03:30:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-12346"
},
{
"type": "WEB",
"url": "https://note-hxlab.wetolink.com/share/8QmDZCddHvyR"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.330136"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.330136"
},
{
"type": "WEB",
"url": "https://vuldb.com/?submit.674551"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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-CFPX-JVFR-XH8W
Vulnerability from github – Published: 2022-05-14 02:19 – Updated: 2022-05-14 02:19CeLa Link CLR-M20 devices allow unauthorized users to upload any file (e.g., asp, aspx, cfm, html, jhtml, jsp, or shtml), which causes remote code execution as well. Because of the WebDAV feature, it is possible to upload arbitrary files by utilizing the PUT method.
{
"affected": [],
"aliases": [
"CVE-2018-15137"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-08-08T00:29:00Z",
"severity": "CRITICAL"
},
"details": "CeLa Link CLR-M20 devices allow unauthorized users to upload any file (e.g., asp, aspx, cfm, html, jhtml, jsp, or shtml), which causes remote code execution as well. Because of the WebDAV feature, it is possible to upload arbitrary files by utilizing the PUT method.",
"id": "GHSA-cfpx-jvfr-xh8w",
"modified": "2022-05-14T02:19:40Z",
"published": "2022-05-14T02:19:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-15137"
},
{
"type": "WEB",
"url": "https://github.com/safakaslan/CelaLinkCLRM20/issues/1"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/45021"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CFR3-GGCX-JJF3
Vulnerability from github – Published: 2026-07-31 09:31 – Updated: 2026-07-31 09:31The Realtyna Organic IDX plugin + WPL Real Estate plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 5.2.0 via the upload function. This is due to missing file type validation in the upload function, combined with a publicly accessible I/O endpoint authenticated solely by static, plugin-seeded API credentials that are identical across all installations. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. The WPL I/O service endpoint is registered on the public WordPress init hook with no WordPress capability check, and the required api_key and api_secret values are static defaults seeded by the plugin's own SQL migration files, meaning any unauthenticated attacker who knows these publicly documented defaults can reach and exploit the vulnerable upload path.
{
"affected": [],
"aliases": [
"CVE-2026-14483"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-31T07:16:24Z",
"severity": "CRITICAL"
},
"details": "The Realtyna Organic IDX plugin + WPL Real Estate plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 5.2.0 via the upload function. This is due to missing file type validation in the upload function, combined with a publicly accessible I/O endpoint authenticated solely by static, plugin-seeded API credentials that are identical across all installations. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. The WPL I/O service endpoint is registered on the public WordPress init hook with no WordPress capability check, and the required api_key and api_secret values are static defaults seeded by the plugin\u0027s own SQL migration files, meaning any unauthenticated attacker who knows these publicly documented defaults can reach and exploit the vulnerable upload path.",
"id": "GHSA-cfr3-ggcx-jjf3",
"modified": "2026-07-31T09:31:17Z",
"published": "2026-07-31T09:31:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-14483"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/real-estate-listing-realtyna-wpl/trunk/assets/migrations/basic/1.0.0.sql#L1119"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/real-estate-listing-realtyna-wpl/trunk/libraries/file.php#L217"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/real-estate-listing-realtyna-wpl/trunk/libraries/io/global.php#L142"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/real-estate-listing-realtyna-wpl/trunk/libraries/io/mobile_application/set_property.php#L39"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/real-estate-listing-realtyna-wpl/trunk/libraries/services/io.php#L20"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/23068a98-623d-4eb3-a7c5-6af410de4320?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CFR5-VJC2-P7GJ
Vulnerability from github – Published: 2022-05-24 17:46 – Updated: 2022-05-24 17:46Directus 8 before 8.8.2 allows remote authenticated users to execute arbitrary code because file-upload permissions include the ability to upload a .php file to the main upload directory and/or upload a .php file and a .htaccess file to a subdirectory. Exploitation succeeds only for certain installations with the Apache HTTP Server and the local-storage driver (e.g., when the product was obtained from hub.docker.com).
{
"affected": [],
"aliases": [
"CVE-2021-29641"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-04-07T22:15:00Z",
"severity": "HIGH"
},
"details": "Directus 8 before 8.8.2 allows remote authenticated users to execute arbitrary code because file-upload permissions include the ability to upload a .php file to the main upload directory and/or upload a .php file and a .htaccess file to a subdirectory. Exploitation succeeds only for certain installations with the Apache HTTP Server and the local-storage driver (e.g., when the product was obtained from hub.docker.com).",
"id": "GHSA-cfr5-vjc2-p7gj",
"modified": "2022-05-24T17:46:54Z",
"published": "2022-05-24T17:46:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29641"
},
{
"type": "WEB",
"url": "https://hub.docker.com/layers/directus/directus/v8.8.2-apache/images/sha256-d9898b6442b0150c3c377b50e706757f35d2d563bd82ddaf97f3ae4ba450a6e6?context=explore"
},
{
"type": "WEB",
"url": "https://sec-consult.com/de/vulnerability-lab/advisory/arbitrary-file-upload-and-bypassing-htaccess-rules-in-monospace-directus-headless-cms"
},
{
"type": "WEB",
"url": "https://sec-consult.com/vulnerability-lab/advisory/arbitrary-file-upload-and-bypassing-htaccess-rules-in-monospace-directus-headless-cms"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/162118/Monospace-Directus-Headless-CMS-File-Upload-Rule-Bypass.html"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2021/Apr/14"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-CG4W-83Q5-49GW
Vulnerability from github – Published: 2022-04-26 00:00 – Updated: 2022-05-04 00:00The SP Project & Document Manager WordPress plugin before 4.24 allows any authenticated users, such as subscribers, to upload files. The plugin attempts to prevent PHP and other similar files that could be executed on the server from being uploaded by checking the file extension. It was discovered that on Windows servers, the security checks in place were insufficient, enabling bad actors to potentially upload backdoors on vulnerable sites.
{
"affected": [],
"aliases": [
"CVE-2021-4225"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-04-25T16:16:00Z",
"severity": "HIGH"
},
"details": "The SP Project \u0026 Document Manager WordPress plugin before 4.24 allows any authenticated users, such as subscribers, to upload files. The plugin attempts to prevent PHP and other similar files that could be executed on the server from being uploaded by checking the file extension. It was discovered that on Windows servers, the security checks in place were insufficient, enabling bad actors to potentially upload backdoors on vulnerable sites.",
"id": "GHSA-cg4w-83q5-49gw",
"modified": "2022-05-04T00:00:31Z",
"published": "2022-04-26T00:00:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-4225"
},
{
"type": "WEB",
"url": "https://github.com/pang0lin/CVEproject/blob/main/wordpress_SP-Project_fileupload.md"
},
{
"type": "WEB",
"url": "https://wpscan.com/vulnerability/bd1083d1-edcc-482e-a8a9-c8b6c8d417bd"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CG57-P69R-3M7P
Vulnerability from github – Published: 2022-02-10 23:46 – Updated: 2021-05-19 17:48Matrix-React-SDK is a react-based SDK for inserting a Matrix chat/voip client into a web page. Before version 3.21.0, when uploading a file, the local file preview can lead to execution of scripts embedded in the uploaded file. This can only occur after several user interactions to open the preview in a separate tab. This only impacts the local user while in the process of uploading. It cannot be exploited remotely or by other users. This vulnerability is patched in version 3.21.0.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "matrix-react-sdk"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.21.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-32622"
],
"database_specific": {
"cwe_ids": [
"CWE-434",
"CWE-74"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-19T17:48:44Z",
"nvd_published_at": "2021-05-17T20:15:00Z",
"severity": "MODERATE"
},
"details": "Matrix-React-SDK is a react-based SDK for inserting a Matrix chat/voip client into a web page. Before version 3.21.0, when uploading a file, the local file preview can lead to execution of scripts embedded in the uploaded file. This can only occur after several user interactions to open the preview in a separate tab. This only impacts the local user while in the process of uploading. It cannot be exploited remotely or by other users. This vulnerability is patched in version 3.21.0.",
"id": "GHSA-cg57-p69r-3m7p",
"modified": "2021-05-19T17:48:44Z",
"published": "2022-02-10T23:46:51Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/matrix-org/matrix-react-sdk/security/advisories/GHSA-8796-gc9j-63rv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32622"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/matrix-react-sdk/pull/5981"
},
{
"type": "WEB",
"url": "https://www.npmjs.com/package/matrix-react-sdk"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "Improper file handling in matrix-react-sdk"
}
GHSA-CG64-6498-7HPC
Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-06-17 18:35Unauthenticated Arbitrary File Upload in SigmaForms Pro – AI Generated Forms <= 1.4.5 versions.
{
"affected": [],
"aliases": [
"CVE-2026-52705"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-17T13:20:49Z",
"severity": "CRITICAL"
},
"details": "Unauthenticated Arbitrary File Upload in SigmaForms Pro \u2013 AI Generated Forms \u003c= 1.4.5 versions.",
"id": "GHSA-cg64-6498-7hpc",
"modified": "2026-06-17T18:35:52Z",
"published": "2026-06-17T18:35:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52705"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/wordpress/plugin/sigmaforms-pro/vulnerability/wordpress-sigmaforms-pro-ai-generated-forms-plugin-1-4-5-arbitrary-file-upload-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CGPG-6265-G3WP
Vulnerability from github – Published: 2025-10-03 12:33 – Updated: 2025-10-03 12:33The AP Background plugin for WordPress is vulnerable to arbitrary file uploads due to missing authorization and insufficient file validation within the advParallaxBackAdminSaveSlider() handler in versions 3.8.1 to 3.8.2. This makes it possible for authenticated attackers, with Subscriber-level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible.
{
"affected": [],
"aliases": [
"CVE-2025-9561"
],
"database_specific": {
"cwe_ids": [
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-03T12:15:48Z",
"severity": "HIGH"
},
"details": "The AP Background plugin for WordPress is vulnerable to arbitrary file uploads due to missing authorization and insufficient file validation within the advParallaxBackAdminSaveSlider() handler in versions 3.8.1 to 3.8.2. This makes it possible for authenticated attackers, with Subscriber-level access and above, to upload arbitrary files on the affected site\u0027s server which may make remote code execution possible.",
"id": "GHSA-cgpg-6265-g3wp",
"modified": "2025-10-03T12:33:16Z",
"published": "2025-10-03T12:33:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-9561"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/ap-background/tags/3.8.2/includes/functions.admin.php"
},
{
"type": "WEB",
"url": "https://wordpress.org/plugins/ap-background"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/e4045a2b-2bbc-4335-b6d2-af7a046f1f92?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:H/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation
Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.[REF-422] [REF-423]
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
Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically. [REF-423]
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.
- For example, limiting filenames to alphanumeric characters can help to restrict the introduction of unintended file extensions.
Mitigation
Define a very limited set of allowable extensions and only generate filenames that end in these extensions. Consider the possibility of XSS (CWE-79) before allowing .html or .htm file types.
Mitigation
Strategy: Input Validation
Ensure that only one extension is used in the filename. Some web servers, including some versions of Apache, may process files based on inner extensions so that "filename.php.gif" is fed to the PHP interpreter.[REF-422] [REF-423]
Mitigation
When running on a web server that supports case-insensitive filenames, perform case-insensitive evaluations of the extensions that are provided.
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
Do not rely exclusively on sanity checks of file contents to ensure that the file is of the expected type and size. It may be possible for an attacker to hide code in some file segments that will still be executed by the server. For example, GIF images may contain a free-form comments field.
Mitigation
Do not rely exclusively on the MIME content type or filename attribute when determining how to render a file. Validating the MIME content type and ensuring that it matches the extension is only a partial solution.
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Mitigation MIT-22
Strategy: Sandbox or Jail
- Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
- OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs
In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.