CWE-22
Allowed-with-ReviewImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Abstraction: Base · Status: Stable
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
13030 vulnerabilities reference this CWE, most recent first.
GHSA-3P5G-F8F7-7M9H
Vulnerability from github – Published: 2026-05-11 21:31 – Updated: 2026-05-13 18:30A parsing issue in the handling of directory paths was addressed with improved path validation. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. An app may be able to gain root privileges.
{
"affected": [],
"aliases": [
"CVE-2026-28915"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-11T21:18:54Z",
"severity": "HIGH"
},
"details": "A parsing issue in the handling of directory paths was addressed with improved path validation. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. An app may be able to gain root privileges.",
"id": "GHSA-3p5g-f8f7-7m9h",
"modified": "2026-05-13T18:30:40Z",
"published": "2026-05-11T21:31:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28915"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/127115"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/127116"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/127117"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-3P5J-546V-Q985
Vulnerability from github – Published: 2022-05-17 05:17 – Updated: 2022-05-17 05:17Directory traversal vulnerability in the Web UI in EMC Data Protection Advisor (DPA) 5.6 through SP1, 5.7 through SP1, and 5.8 through SP4 allows remote attackers to read arbitrary files via unspecified vectors.
{
"affected": [],
"aliases": [
"CVE-2012-4616"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2012-12-26T20:55:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in the Web UI in EMC Data Protection Advisor (DPA) 5.6 through SP1, 5.7 through SP1, and 5.8 through SP4 allows remote attackers to read arbitrary files via unspecified vectors.",
"id": "GHSA-3p5j-546v-q985",
"modified": "2022-05-17T05:17:45Z",
"published": "2022-05-17T05:17:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2012-4616"
},
{
"type": "WEB",
"url": "http://archives.neohapsis.com/archives/bugtraq/2012-12/0125.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3P62-P8GH-RH2W
Vulnerability from github – Published: 2026-05-05 06:31 – Updated: 2026-05-05 06:31A vulnerability has been found in 54yyyu code-mcp up to 4cfc4643541a110c906d93635b391bf7e357f4a8. The affected element is the function is_safe_path of the file src/code_mcp/server.py of the component MCP File Handler. Such manipulation leads to path traversal. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. This product takes the approach of rolling releases to provide continious delivery. Therefore, version details for affected and updated releases are not available. The project was informed of the problem early through an issue report but has not responded yet.
{
"affected": [],
"aliases": [
"CVE-2026-7811"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-05T05:16:00Z",
"severity": "MODERATE"
},
"details": "A vulnerability has been found in 54yyyu code-mcp up to 4cfc4643541a110c906d93635b391bf7e357f4a8. The affected element is the function is_safe_path of the file src/code_mcp/server.py of the component MCP File Handler. Such manipulation leads to path traversal. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. This product takes the approach of rolling releases to provide continious delivery. Therefore, version details for affected and updated releases are not available. The project was informed of the problem early through an issue report but has not responded yet.",
"id": "GHSA-3p62-p8gh-rh2w",
"modified": "2026-05-05T06:31:06Z",
"published": "2026-05-05T06:31:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-7811"
},
{
"type": "WEB",
"url": "https://github.com/54yyyu/code-mcp/issues/4"
},
{
"type": "WEB",
"url": "https://github.com/54yyyu/code-mcp"
},
{
"type": "WEB",
"url": "https://vuldb.com/submit/807751"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/361071"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/361071/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-3P6X-7VMM-W6RR
Vulnerability from github – Published: 2022-07-12 00:00 – Updated: 2022-07-16 00:00The ceee-vip/cockybook repository through 2015-04-16 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.
{
"affected": [],
"aliases": [
"CVE-2022-31572"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-07-11T01:15:00Z",
"severity": "CRITICAL"
},
"details": "The ceee-vip/cockybook repository through 2015-04-16 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.",
"id": "GHSA-3p6x-7vmm-w6rr",
"modified": "2022-07-16T00:00:28Z",
"published": "2022-07-12T00:00:58Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31572"
},
{
"type": "WEB",
"url": "https://github.com/github/securitylab/issues/669#issuecomment-1117265726"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-3P8V-W8MR-M3X8
Vulnerability from github – Published: 2024-10-24 18:16 – Updated: 2024-10-24 21:46Summary
The Butterfly framework uses the java.net.URL class to refer to (what are expected to be) local resource files, like images or templates. This works: "opening a connection" to these URLs opens the local file. However, if a file:/ URL is directly given where a relative path (resource name) is expected, this is also accepted in some code paths; the app then fetches the file, from a remote machine if indicated, and uses it as if it was a trusted part of the app's codebase.
This leads to multiple weaknesses and potential weaknesses:
- An attacker that has network access to the application could use it to gain access to files, either on the the server's filesystem (path traversal) or shared by nearby machines (server-side request forgery with e.g. SMB).
- An attacker that can lead or redirect a user to a crafted URL belonging to the app could cause arbitrary attacker-controlled JavaScript to be loaded in the victim's browser (cross-site scripting).
- If an app is written in such a way that an attacker can influence the resource name used for a template, that attacker could cause the app to fetch and execute an attacker-controlled template (remote code execution).
Details
The edu.mit.simile.butterfly.ButterflyModuleImpl.getResource method converts a resource name into an URL, for instance:
images/logo-gem-126.svg
file:/C:/Users/Wander/IdeaProjects/OpenRefine/main/webapp/modules/core/images/logo-gem-126.svg
If the resource name already starts with file:/, it is passed through unmodified (line 287). There is no check that the resulting URL is inside the expected directory or on the same machine.
The default implementation for process in ButterflyModuleImpl is to serve a named resource, which makes it vulnerable. The Velocity template library is bound to the same getResource implementation through the ButterflyResourceLoader class, which means it is also vulnerable if template resource names can somehow be influenced by an attacker.
PoC
This demonstration has been tested with OpenRefine on a Windows machine. Start OpenRefine, create a file (here example.js) with some contents, then concatenate the OpenRefine URL and its file:/ URL, as follows:
http://localhost:3333/file:/C:/Users/Wander/example.js
The file is read and sent to the browser. Then, visit:
http://localhost:3333/file:%2f%2fwandernauta.nl/public/demo.html
Assuming there are no firewalls in the way, the HTML page is retrieved from the public SMB (Samba) network share and sent to the browser, which executes the embedded JavaScript.
In the case of OpenRefine specifically, to demonstrate the attacker-controlled template name case:
http://localhost:3333/file:%2f%2fwandernauta.nl/public/index
An index.vt template containing the snippet above is retrieved from the same share, which is then executed; the Windows calculator opens.
Impact
Depending on how the framework is used: path traversal, XSS, SSRF; potentially RCE.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.openrefine.dependencies:butterfly"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2.6"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-47883"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-36",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2024-10-24T18:16:43Z",
"nvd_published_at": "2024-10-24T21:15:13Z",
"severity": "CRITICAL"
},
"details": "### Summary\n\nThe Butterfly framework uses the `java.net.URL` class to refer to (what are expected to be) local resource files, like images or templates. This works: \"opening a connection\" to these URLs opens the local file. However, if a `file:/` URL is directly given where a relative path (resource name) is expected, this is also accepted in some code paths; the app then fetches the file, from a remote machine if indicated, and uses it as if it was a trusted part of the app\u0027s codebase.\n\nThis leads to multiple weaknesses and potential weaknesses:\n\n* An attacker that has network access to the application could use it to gain access to files, either on the the server\u0027s filesystem (path traversal) or shared by nearby machines (server-side request forgery with e.g. SMB).\n* An attacker that can lead or redirect a user to a crafted URL belonging to the app could cause arbitrary attacker-controlled JavaScript to be loaded in the victim\u0027s browser (cross-site scripting).\n* If an app is written in such a way that an attacker can influence the resource name used for a template, that attacker could cause the app to fetch and execute an attacker-controlled template (remote code execution).\n\n### Details\n\nThe `edu.mit.simile.butterfly.ButterflyModuleImpl.getResource` method converts a resource name into an URL, for instance:\n\n```\nimages/logo-gem-126.svg\nfile:/C:/Users/Wander/IdeaProjects/OpenRefine/main/webapp/modules/core/images/logo-gem-126.svg\n```\n\nIf the resource name already starts with `file:/`, it is passed through unmodified (line 287). There is no check that the resulting URL is inside the expected directory or on the same machine.\n\nThe default implementation for `process` in `ButterflyModuleImpl` is to serve a named resource, which makes it vulnerable. The Velocity template library is bound to the same `getResource` implementation through the `ButterflyResourceLoader` class, which means it is also vulnerable if template resource names can somehow be influenced by an attacker.\n\n### PoC\n\nThis demonstration has been tested with [OpenRefine](https://github.com/OpenRefine/OpenRefine) on a Windows machine. Start OpenRefine, create a file (here `example.js`) with some contents, then concatenate the OpenRefine URL and its `file:/` URL, as follows:\n\n http://localhost:3333/file:/C:/Users/Wander/example.js\n\nThe file is read and sent to the browser. Then, visit:\n\n http://localhost:3333/file:%2f%2fwandernauta.nl/public/demo.html\n\nAssuming there are no firewalls in the way, the HTML page is retrieved from the public SMB (Samba) network share and sent to the browser, which executes the embedded JavaScript.\n\nIn the case of OpenRefine specifically, to demonstrate the attacker-controlled template name case:\n\n http://localhost:3333/file:%2f%2fwandernauta.nl/public/index\n\nAn `index.vt` template containing the snippet above is retrieved from the same share, which is then executed; the Windows calculator opens.\n\n### Impact\n\nDepending on how the framework is used: path traversal, XSS, SSRF; potentially RCE.",
"id": "GHSA-3p8v-w8mr-m3x8",
"modified": "2024-10-24T21:46:18Z",
"published": "2024-10-24T18:16:43Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/OpenRefine/simile-butterfly/security/advisories/GHSA-3p8v-w8mr-m3x8"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-47883"
},
{
"type": "WEB",
"url": "https://github.com/OpenRefine/simile-butterfly/commit/537f64bfa72746f8b21d4bda461fad843435319c"
},
{
"type": "PACKAGE",
"url": "https://github.com/OpenRefine/simile-butterfly"
}
],
"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:N",
"type": "CVSS_V3"
}
],
"summary": "Butterfly has path/URL confusion in resource handling leading to multiple weaknesses"
}
GHSA-3P96-WRM7-XC3M
Vulnerability from github – Published: 2024-07-12 18:31 – Updated: 2024-07-12 21:31An arbitrary file upload vulnerability in the component /admin/cmsTemplate/savePlaceMetaData of Public CMS v.4.0.202302.e allows attackers to execute arbitrary code via uploading a crafted file.
{
"affected": [],
"aliases": [
"CVE-2024-40550"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T16:15:05Z",
"severity": "HIGH"
},
"details": "An arbitrary file upload vulnerability in the component /admin/cmsTemplate/savePlaceMetaData of Public CMS v.4.0.202302.e allows attackers to execute arbitrary code via uploading a crafted file.",
"id": "GHSA-3p96-wrm7-xc3m",
"modified": "2024-07-12T21:31:17Z",
"published": "2024-07-12T18:31:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40550"
},
{
"type": "WEB",
"url": "https://gitee.com/sanluan/PublicCMS/issues/IAALWJ"
}
],
"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-3PC2-C878-63RJ
Vulnerability from github – Published: 2023-07-06 19:24 – Updated: 2024-04-04 05:37A path traversal vulnerability in the “account_print.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker with administrator privileges to execute unauthorized OS commands in the “tmp” directory by uploading a crafted file if the hotspot function were enabled.
{
"affected": [],
"aliases": [
"CVE-2023-22914"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-04-24T17:15:09Z",
"severity": "HIGH"
},
"details": "A path traversal vulnerability in the \u201caccount_print.cgi\u201d CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker with administrator privileges to execute unauthorized OS commands in the \u201ctmp\u201d directory by uploading a crafted file if the hotspot function were enabled.",
"id": "GHSA-3pc2-c878-63rj",
"modified": "2024-04-04T05:37:56Z",
"published": "2023-07-06T19:24:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-22914"
},
{
"type": "WEB",
"url": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-of-firewalls-and-aps"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-3PG8-3336-W32H
Vulnerability from github – Published: 2022-05-17 04:12 – Updated: 2025-04-12 12:48Directory traversal vulnerability in UploadServlet in the Remote Management component in Novell ZENworks Configuration Management (ZCM) 10 before 10.3 allows remote attackers to execute arbitrary code via a crafted WAR pathname in the filename parameter in conjunction with WAR content in the POST data, a different vulnerability than CVE-2010-5324.
{
"affected": [],
"aliases": [
"CVE-2010-5323"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-06-07T23:59:00Z",
"severity": "HIGH"
},
"details": "Directory traversal vulnerability in UploadServlet in the Remote Management component in Novell ZENworks Configuration Management (ZCM) 10 before 10.3 allows remote attackers to execute arbitrary code via a crafted WAR pathname in the filename parameter in conjunction with WAR content in the POST data, a different vulnerability than CVE-2010-5324.",
"id": "GHSA-3pg8-3336-w32h",
"modified": "2025-04-12T12:48:30Z",
"published": "2022-05-17T04:12:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2010-5323"
},
{
"type": "WEB",
"url": "https://bugzilla.novell.com/show_bug.cgi?id=578911"
},
{
"type": "WEB",
"url": "https://www.novell.com/support/kb/doc.php?id=7005573"
},
{
"type": "WEB",
"url": "http://www.exploit-db.com/exploits/16784"
},
{
"type": "WEB",
"url": "http://www.zerodayinitiative.com/advisories/ZDI-10-078"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3PGG-HVFR-3PHX
Vulnerability from github – Published: 2022-05-17 00:15 – Updated: 2025-04-20 03:49An issue was discovered in Squiz Matrix from 5.3 through to 5.3.6.1 and 5.4.1.3. An information disclosure caused by a Path Traversal issue in the 'File Bridge' plugin allowed the existence of files outside of the bridged path to be confirmed.
{
"affected": [],
"aliases": [
"CVE-2017-14196"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-11-30T02:29:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in Squiz Matrix from 5.3 through to 5.3.6.1 and 5.4.1.3. An information disclosure caused by a Path Traversal issue in the \u0027File Bridge\u0027 plugin allowed the existence of files outside of the bridged path to be confirmed.",
"id": "GHSA-3pgg-hvfr-3phx",
"modified": "2025-04-20T03:49:14Z",
"published": "2022-05-17T00:15:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-14196"
},
{
"type": "WEB",
"url": "http://devalias.net/devalias/2017/09/07/squiz-matrix-multiple-vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3PH4-Q4PX-CWQ5
Vulnerability from github – Published: 2022-05-02 03:24 – Updated: 2022-05-02 03:24Directory traversal vulnerability in cms_detect.php in TotalCalendar 2.4 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the include parameter.
{
"affected": [],
"aliases": [
"CVE-2009-1406"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2009-04-24T14:30:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in cms_detect.php in TotalCalendar 2.4 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the include parameter.",
"id": "GHSA-3ph4-q4px-cwq5",
"modified": "2022-05-02T03:24:38Z",
"published": "2022-05-02T03:24:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2009-1406"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/49980"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/8503"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/34824"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/34634"
}
],
"schema_version": "1.4.0",
"severity": []
}
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 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-20.1
Strategy: Input Validation
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
- 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). This includes:
- realpath() in C
- getCanonicalPath() in Java
- GetFullPath() in ASP.NET
- realpath() or abs_path() in Perl
- realpath() in PHP
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].
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-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-21.1
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.
- For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
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.
Mitigation MIT-34
Strategy: Attack Surface Reduction
- Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately.
- This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
Mitigation MIT-39
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
- In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
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-126: Path Traversal
An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
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-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.