CVE-2021-21703

Severity CVSS v4.0:

Pending analysis

Type:

CWE-787 Out-of-bounds Write

Publication date:

25/10/2021

Last modified:

07/11/2023

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.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.00 HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.00

Severity 3.x

HIGH

Vector 2.0

AV:L/AC:M/Au:N/C:C/I:C/A:C CVSS v2.0 Severity and Metrics:

Base Score: 6.90 MEDIUM
Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C

Attack Vector (AV): Local
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Complete
Integrity (I): Complete
Availability (A): Complete

Base Score 2.0

6.90

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:php:php::::::::	7.3.0 (including)	7.3.31 (including)
cpe:2.3:a:php:php::::::::	7.4.0 (including)	7.4.25 (excluding)
cpe:2.3:a:php:php::::::::	8.0.0 (including)	8.0.12 (excluding)
cpe:2.3:o:debian:debian_linux:9.0:::::::*
cpe:2.3:o:debian:debian_linux:10.0:::::::*
cpe:2.3:o:debian:debian_linux:11.0:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*
cpe:2.3:o:fedoraproject:fedora:34:::::::*
cpe:2.3:o:fedoraproject:fedora:35:::::::*
cpe:2.3:a:netapp:clustered_data_ontap:-:::::::*
cpe:2.3:a:oracle:communications_diameter_signaling_router::::::::	8.0.0.0 (including)	8.5.0.2 (including)

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-21703

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools