title: Grav Server-side Template Injection (SSTI) via Twig Default Filters
description: Grav is a flat-file content management system. Prior to version 1.7.42, the patch for CVE-2022-2073, a server-side template injection vulnerability in Grav leveraging the default `filter()` function, did not block other built-in functions exposed by Twig's Core Extension that could be used to invoke arbitrary unsafe functions, thereby allowing for remote code execution. A patch in version 1.74.2 overrides the built-in Twig `map()` and `reduce()` filter functions in `system/src/Grav/Common/Twig/Extension/GravExtension.php` to validate the argument passed to the filter in `$arrow`.
problem types: CWE-20: Improper Input Validation
affected:
{
vendor: getgrav
product: grav
versions:
version: < 1.7.42, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
version: 3.1
]