title: mb_strtolower (UTF-32LE): stack-buffer-overflow at php_unicode_tolower_full
description: In PHP versions 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while using mb_strtolower() function with UTF-32LE encoding, certain invalid strings could cause PHP to overwrite stack-allocated buffer. This could lead to memory corruption, crashes and potentially code execution.
problem types: CWE-121 Stack-based Buffer Overflow
affected:
{
product: PHP
vendor: PHP Group
versions:
lessThan: 7.3.16, status: affected, version: 7.3.x, versionType: custom
lessThan: 7.4.4, status: affected, version: 7.4.x, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.4
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: HIGH
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
version: 3.1
]