title: PHP-FPM memory access in root process leading to privilege escalation
description: In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
problem types: CWE-787 Out-of-bounds Write
affected:
{
product: PHP
vendor: PHP Group
versions:
lessThanOrEqual: 7.3.31, status: affected, version: 7.3.x, versionType: custom
lessThan: 7.4.25, status: affected, version: 7.4.x, versionType: custom
lessThan: 8.0.12, status: affected, version: 8.0.X, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 7.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
version: 3.1
]