CVE-2021-21703

Advisory lineage Upstream: 0 Downstream: 21
Modified
Published: 25 Oct 2021, 05:40
Last modified:17 Sept 2024, 03:02

Vulnerability Summary

Overall Risk (default)
medium
41/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.14% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

25 Oct 2021, 05:40
Published
Vulnerability first disclosed
17 Sept 2024, 03:02
Last Modified
Vulnerability information updated

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 Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
  • v3.1•HIGH•Score: 7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  • v2.0•MEDIUM•Score: 6.9AV:L/AC:M/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.14%• Percentile: 34%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

  • CWE-284•Improper Access Control

    The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected Systems

  • debian•debian_linux

    9.0 | 10.0 | 11.0

  • fedoraproject•fedora

    33 | 34 | 35

  • netapp•clustered_data_ontap

    na

  • oracle•communications_diameter_signaling_router

    ≥ 8.0.0.0, ≤ 8.5.0.2

  • Unknown•PHP

    ≥ 7.3.x, ≤ 7.3.31 | ≥ 7.4.x, < 7.4.25 | ≥ 8.0.X, < 8.0.12

  • Unknown•PHP

    ≥ 7.3.0, ≤ 7.3.31 | ≥ 7.4.0, < 7.4.25 | ≥ 8.0.0, < 8.0.12

References (12)