Use After Free Affecting php-bcmath package, versions <0:7.4.30-1.module+el8.7.0+15886+8e29b882


Severity

Recommended
medium

Based on CentOS security rating.

Threat Intelligence

EPSS
0.44% (76th percentile)

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  • Snyk IDSNYK-CENTOS8-PHPBCMATH-2405801
  • published18 Feb 2022
  • disclosed17 Feb 2022

Introduced: 17 Feb 2022

CVE-2021-21708  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Centos:8 php-bcmath to version 0:7.4.30-1.module+el8.7.0+15886+8e29b882 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream php-bcmath package and not the php-bcmath package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.

CVSS Scores

version 3.1