Overview
- Description
- Grav is a flat-file content management system. Prior to version 1.7.42, there is a logic flaw in the `GravExtension.filterFilter()` function whereby validation against a denylist of unsafe functions is only performed when the argument passed to filter is a string. However, passing an array as a callable argument allows the validation check to be skipped. Consequently, a low privileged attacker with login access to Grav Admin panel and page creation/update permissions is able to inject malicious templates to obtain remote code execution. The vulnerability can be found in the `GravExtension.filterFilter()` function declared in `/system/src/Grav/Common/Twig/Extension/GravExtension.php`. Version 1.7.42 contains a patch for this issue. End users should also ensure that `twig.undefined_functions` and `twig.undefined_filters` properties in `/path/to/webroot/system/config/system.yaml` configuration file are set to `false` to disallow Twig from treating undefined filters/functions as PHP functions and executing them.
- Source
- security-advisories@github.com
- NVD status
- Modified
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 7.2
- Impact score
- 5.9
- Exploitability score
- 1.2
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Severity
- HIGH
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "758F84B9-A2EC-45D8-86DD-B309DB02B9AE",
"versionEndExcluding": "1.7.42"
}
],
"operator": "OR"
}
]
}
]