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.
913 vulnerabilities reference this CWE, most recent first.
GHSA-75M5-HH4R-Q9GX
Vulnerability from github – Published: 2024-03-20 15:01 – Updated: 2024-03-20 21:04Summary
An arbitrary file renaming vulnerability exists that enables an authenticated administrator with permissions to modify stores through the REST Coverage Store or Data Store API to rename arbitrary files and directories with a name that does not end in ".zip".
Details
Store file uploads rename zip files to have a ".zip" extension if it doesn't already have one before unzipping the file. This is fine for file and url upload methods where the files will be in a specific subdirectory of the data directory but, when using the external upload method, this allows arbitrary files and directories to be renamed.
PoC
Coverage Store Example (workspace and store name are irrelevant and any valid coverage format can be used): curl -XPUT -H"Content-Type:application/zip" -u"admin:geoserver" -d"/file/to/move" "http://localhost:8080/geoserver/rest/workspaces/a/coveragestores/b/external.geotiff" Data Store Example (workspace and store name and data store format are irrelevant): curl -XPUT -H"Content-Type:application/zip" -u"admin:geoserver" -d"/file/to/move" "http://localhost:8080/geoserver/rest/workspaces/a/datastores/b/external.c"
Impact
Renaming GeoServer files will most likely result in a denial of service, either completely preventing GeoServer from running or effectively deleting specific resources (such as a workspace, layer or style). In some cases, renaming GeoServer files could revert to the default settings for that file which could be relatively harmless like removing contact information or have more serious consequences like allowing users to make OGC requests that the customized settings would have prevented them from making. The impact of renaming non-GeoServer files depends on the specific environment although some sort of denial of service is a likely outcome.
References
https://osgeo-org.atlassian.net/browse/GEOS-11213 https://github.com/geoserver/geoserver/pull/7289
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.geoserver:gs-restconfig"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.23.5"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.geoserver:gs-restconfig"
},
"ranges": [
{
"events": [
{
"introduced": "2.24.0"
},
{
"fixed": "2.24.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-23634"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-73"
],
"github_reviewed": true,
"github_reviewed_at": "2024-03-20T15:01:48Z",
"nvd_published_at": "2024-03-20T16:15:07Z",
"severity": "MODERATE"
},
"details": "### Summary\nAn arbitrary file renaming vulnerability exists that enables an authenticated administrator with permissions to modify stores through the REST Coverage Store or Data Store API to rename arbitrary files and directories with a name that does not end in \".zip\".\n\n### Details\nStore file uploads rename zip files to have a \".zip\" extension if it doesn\u0027t already have one before unzipping the file. This is fine for file and url upload methods where the files will be in a specific subdirectory of the data directory but, when using the external upload method, this allows arbitrary files and directories to be renamed.\n\n### PoC\nCoverage Store Example (workspace and store name are irrelevant and any valid coverage format can be used):\ncurl -XPUT -H\"Content-Type:application/zip\" -u\"admin:geoserver\" -d\"/file/to/move\" \"http://localhost:8080/geoserver/rest/workspaces/a/coveragestores/b/external.geotiff\"\nData Store Example (workspace and store name and data store format are irrelevant):\ncurl -XPUT -H\"Content-Type:application/zip\" -u\"admin:geoserver\" -d\"/file/to/move\" \"http://localhost:8080/geoserver/rest/workspaces/a/datastores/b/external.c\"\n\n### Impact\nRenaming GeoServer files will most likely result in a denial of service, either completely preventing GeoServer from running or effectively deleting specific resources (such as a workspace, layer or style). In some cases, renaming GeoServer files could revert to the default settings for that file which could be relatively harmless like removing contact information or have more serious consequences like allowing users to make OGC requests that the customized settings would have prevented them from making. The impact of renaming non-GeoServer files depends on the specific environment although some sort of denial of service is a likely outcome.\n\n### References\nhttps://osgeo-org.atlassian.net/browse/GEOS-11213\nhttps://github.com/geoserver/geoserver/pull/7289\n",
"id": "GHSA-75m5-hh4r-q9gx",
"modified": "2024-03-20T21:04:06Z",
"published": "2024-03-20T15:01:48Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/geoserver/geoserver/security/advisories/GHSA-75m5-hh4r-q9gx"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-23634"
},
{
"type": "WEB",
"url": "https://github.com/geoserver/geoserver/pull/7289"
},
{
"type": "WEB",
"url": "https://github.com/geoserver/geoserver/commit/5d6af2f8ba9ad7dffae59575504a867159698772"
},
{
"type": "WEB",
"url": "https://github.com/geoserver/geoserver/commit/c37f58fbacdfa0d581a6f99195585f70b1201f0a"
},
{
"type": "PACKAGE",
"url": "https://github.com/geoserver/geoserver"
},
{
"type": "WEB",
"url": "https://osgeo-org.atlassian.net/browse/GEOS-11213"
}
],
"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:H",
"type": "CVSS_V3"
}
],
"summary": "GeoServer Arbitrary file renaming vulnerability in REST Coverage/Data Store API"
}
GHSA-75PX-35P4-QQ6H
Vulnerability from github – Published: 2025-03-20 12:32 – Updated: 2025-03-21 18:57A vulnerability in aimhubio/aim version 3.19.3 allows an attacker to exploit the tarfile.extractall() function to extract the contents of a maliciously crafted tarfile to arbitrary locations on the host server. The attacker can control repo.path and run_hash to bypass directory existence checks and extract files to unintended locations, potentially overwriting critical files. This can lead to arbitrary data being written to arbitrary locations on the remote tracking server, which could be used for further attacks such as writing a new SSH key to the target server.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "aim"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "3.19.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-6829"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": true,
"github_reviewed_at": "2025-03-21T18:57:32Z",
"nvd_published_at": "2025-03-20T10:15:33Z",
"severity": "CRITICAL"
},
"details": "A vulnerability in aimhubio/aim version 3.19.3 allows an attacker to exploit the `tarfile.extractall()` function to extract the contents of a maliciously crafted tarfile to arbitrary locations on the host server. The attacker can control `repo.path` and `run_hash` to bypass directory existence checks and extract files to unintended locations, potentially overwriting critical files. This can lead to arbitrary data being written to arbitrary locations on the remote tracking server, which could be used for further attacks such as writing a new SSH key to the target server.",
"id": "GHSA-75px-35p4-qq6h",
"modified": "2025-03-21T18:57:33Z",
"published": "2025-03-20T12:32:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-6829"
},
{
"type": "PACKAGE",
"url": "https://github.com/aimhubio/aim"
},
{
"type": "WEB",
"url": "https://huntr.com/bounties/7c97065c-1b63-4982-82c1-8038be0ed570"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Aim External Control of File Name or Path vulnerability"
}
GHSA-77VP-2488-VMF6
Vulnerability from github – Published: 2025-10-20 21:30 – Updated: 2025-10-28 18:30External Control of File Name or Path vulnerability in opentext Flipper allows Path Traversal. The vulnerability could allow a user to submit a stored local file path and then download the specified file from the system by requesting the stored document ID.
This issue affects Flipper: 3.1.2.
{
"affected": [],
"aliases": [
"CVE-2025-8048"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-20T20:15:38Z",
"severity": "MODERATE"
},
"details": "External Control of File Name or Path vulnerability in opentext Flipper allows Path Traversal. The vulnerability could allow a user to submit a stored local file\npath and then download the specified file from the system by requesting the\nstored document ID.\n\n\n\n\n\n\n\nThis issue affects Flipper: 3.1.2.",
"id": "GHSA-77vp-2488-vmf6",
"modified": "2025-10-28T18:30:26Z",
"published": "2025-10-20T21:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-8048"
},
{
"type": "WEB",
"url": "https://support.opentext.com/csm?id=ot_kb_unauthenticated\u0026sysparm_article=KB0850531"
}
],
"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"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/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:P/AU:Y/R:U/V:D/RE:M/U:Green",
"type": "CVSS_V4"
}
]
}
GHSA-7869-M4GV-9V2J
Vulnerability from github – Published: 2025-03-01 00:31 – Updated: 2025-03-05 18:32The account file upload functionality in Syspass 3.2.x fails to properly handle special characters in filenames. This mismanagement leads to the disclosure of the web application s source code, exposing sensitive information such as the database password.
{
"affected": [],
"aliases": [
"CVE-2025-25478"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-28T23:15:11Z",
"severity": "MODERATE"
},
"details": "The account file upload functionality in Syspass 3.2.x fails to properly handle special characters in filenames. This mismanagement leads to the disclosure of the web application s source code, exposing sensitive information such as the database password.",
"id": "GHSA-7869-m4gv-9v2j",
"modified": "2025-03-05T18:32:03Z",
"published": "2025-03-01T00:31:55Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-25478"
},
{
"type": "WEB",
"url": "https://github.com/sysentr0py/CVEs/tree/main/CVE-2025-25478"
}
],
"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-78FP-X36M-F5GF
Vulnerability from github – Published: 2025-08-12 18:31 – Updated: 2025-08-12 18:31External control of file name or path in Windows Security App allows an authorized attacker to perform spoofing locally.
{
"affected": [],
"aliases": [
"CVE-2025-53769"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-12T18:15:45Z",
"severity": "MODERATE"
},
"details": "External control of file name or path in Windows Security App allows an authorized attacker to perform spoofing locally.",
"id": "GHSA-78fp-x36m-f5gf",
"modified": "2025-08-12T18:31:32Z",
"published": "2025-08-12T18:31:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53769"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53769"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-79PM-5425-72GV
Vulnerability from github – Published: 2023-06-22 18:30 – Updated: 2024-04-04 05:01Advantech R-SeeNet versions 2.4.22 allows low-level users to access and load the content of local files.
{
"affected": [],
"aliases": [
"CVE-2023-3256"
],
"database_specific": {
"cwe_ids": [
"CWE-610",
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-06-22T17:15:44Z",
"severity": "HIGH"
},
"details": "Advantech R-SeeNet \nversions 2.4.22 \nallows low-level users to access and load the content of local files.\n\n\n\n",
"id": "GHSA-79pm-5425-72gv",
"modified": "2024-04-04T05:01:16Z",
"published": "2023-06-22T18:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-3256"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-23-173-02"
}
],
"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-7F3F-X5F5-79GW
Vulnerability from github – Published: 2025-06-13 09:30 – Updated: 2025-06-17 20:00File contents overwrite the VirtKey class is called when “on-demand pillar” data is requested and uses un-validated input to create paths to the “pki directory”. The functionality is used to auto-accept Minion authentication keys based on a pre-placed “authorization file” at a specific location and is present in the default configuration.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "salt"
},
"ranges": [
{
"events": [
{
"introduced": "3007.0rc1"
},
{
"fixed": "3007.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "salt"
},
"ranges": [
{
"events": [
{
"introduced": "3006.0rc1"
},
{
"fixed": "3006.12"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-22241"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-73"
],
"github_reviewed": true,
"github_reviewed_at": "2025-06-13T21:57:13Z",
"nvd_published_at": "2025-06-13T07:15:21Z",
"severity": "MODERATE"
},
"details": "File contents overwrite the VirtKey class is called when \u201con-demand pillar\u201d data is requested and uses un-validated input to create paths to the \u201cpki directory\u201d. The functionality is used to auto-accept Minion authentication keys based on a pre-placed \u201cauthorization file\u201d at a specific location and is present in the default configuration.",
"id": "GHSA-7f3f-x5f5-79gw",
"modified": "2025-06-17T20:00:42Z",
"published": "2025-06-13T09:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-22241"
},
{
"type": "WEB",
"url": "https://github.com/saltstack/salt/commit/9445f496fed61b15dc4364818007e5b765b0746f"
},
{
"type": "WEB",
"url": "https://docs.saltproject.io/en/3006/topics/releases/3006.12.html"
},
{
"type": "WEB",
"url": "https://docs.saltproject.io/en/3007/topics/releases/3007.4.html"
},
{
"type": "PACKAGE",
"url": "https://github.com/saltstack/salt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Salt\u0027s file contents overwrite the VirtKey class"
}
GHSA-7G39-PMPC-X999
Vulnerability from github – Published: 2026-05-13 21:32 – Updated: 2026-07-14 18:31An arbitrary File Read and Delete Vulnerability in Palo Alto Networks WildFire® WF-500 and WF-500-B appliances enables users to read sensitive information and delete arbitrary files. This vulnerability affects WF-500 and WF-500-B appliances running in the default non-FIPS configuration mode.
The WildFire Appliance (WF-500, WF-500-B) software update is now available to customers that use the WildFire Appliance (WF-500, WF-500-B) for on-premise sandboxing.
Please note that customers using the WildFire Public cloud service are NOT impacted by this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2026-0259"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-13T19:17:01Z",
"severity": "MODERATE"
},
"details": "An arbitrary File Read and Delete Vulnerability in Palo Alto Networks WildFire\u00ae WF-500 and WF-500-B appliances enables users to read sensitive information and delete arbitrary files. This vulnerability affects WF-500 and WF-500-B appliances running in the default non-FIPS configuration mode.\n\n\n\nThe WildFire Appliance (WF-500, WF-500-B) software update is now available to customers that use the WildFire Appliance (WF-500, WF-500-B) for on-premise sandboxing.\n\n\n\nPlease note that customers using the WildFire Public cloud service are NOT impacted by this vulnerability.",
"id": "GHSA-7g39-pmpc-x999",
"modified": "2026-07-14T18:31:46Z",
"published": "2026-05-13T21:32:05Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0259"
},
{
"type": "WEB",
"url": "https://security.paloaltonetworks.com/CVE-2026-0259"
}
],
"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"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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:Y/R:U/V:C/RE:M/U:Amber",
"type": "CVSS_V4"
}
]
}
GHSA-7H46-XXGG-F9Q8
Vulnerability from github – Published: 2025-03-20 12:32 – Updated: 2025-03-20 12:32eosphoros-ai/db-gpt version 0.6.0 contains a vulnerability in the RAG-knowledge endpoint that allows for arbitrary file write. The issue arises from the ability to pass an absolute path to a call to os.path.join, enabling an attacker to write files to arbitrary locations on the target server. This vulnerability can be exploited by setting the doc_file.filename to an absolute path, which can lead to overwriting system files or creating new SSH-key entries.
{
"affected": [],
"aliases": [
"CVE-2024-10834"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-03-20T10:15:20Z",
"severity": "CRITICAL"
},
"details": "eosphoros-ai/db-gpt version 0.6.0 contains a vulnerability in the RAG-knowledge endpoint that allows for arbitrary file write. The issue arises from the ability to pass an absolute path to a call to `os.path.join`, enabling an attacker to write files to arbitrary locations on the target server. This vulnerability can be exploited by setting the `doc_file.filename` to an absolute path, which can lead to overwriting system files or creating new SSH-key entries.",
"id": "GHSA-7h46-xxgg-f9q8",
"modified": "2025-03-20T12:32:40Z",
"published": "2025-03-20T12:32:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-10834"
},
{
"type": "WEB",
"url": "https://huntr.com/bounties/0d598508-151a-4050-9ccd-31bb82955e7a"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7H7J-7VWP-CWFG
Vulnerability from github – Published: 2026-06-15 21:30 – Updated: 2026-06-16 15:33An issue in SNMP4J-Agent 3.8.3 allows a remote attacker to execute arbitrary code via the snmp4jCfgStoragePath component.
{
"affected": [],
"aliases": [
"CVE-2026-39006"
],
"database_specific": {
"cwe_ids": [
"CWE-73"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-15T20:16:27Z",
"severity": "CRITICAL"
},
"details": "An issue in SNMP4J-Agent 3.8.3 allows a remote attacker to execute arbitrary code via the snmp4jCfgStoragePath component.",
"id": "GHSA-7h7j-7vwp-cwfg",
"modified": "2026-06-16T15:33:46Z",
"published": "2026-06-15T21:30:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39006"
},
{
"type": "WEB",
"url": "https://github.com/EaEa0001/security-advisories/blob/main/CVE-2026-39006.md"
}
],
"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"
}
]
}
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.