CVE-2021-21703 Information

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.

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://bugs.php.net/bug.php?id=81026 https://www.debian.org/security/2021/dsa-4993 https://www.debian.org/security/2021/dsa-4992 http://www.openwall.com/lists/oss-security/2021/10/26/7 https://lists.debian.org/debian-lts-announce/2021/10/msg00021.html https://lists.fedoraproject.org/archives/list/[email protected]/message/PBM3KKB3RY2YPOKNMC4HIH7IH3T3WC74/ https://lists.fedoraproject.org/archives/list/[email protected]/message/JO5RA6YOBGGGKLIA6F6BQRZDDECF5L3R/ https://lists.fedoraproject.org/archives/list/[email protected]/message/6PZVLICZUJMXOGWOUWSBAEGIVTF6Y6V3/ https://security.netapp.com/advisory/ntap-20211118-0003/ https://www.oracle.com/security-alerts/cpujan2022.html https://www.oracle.com/security-alerts/cpuapr2022.html

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.0