Use After Free Affecting php7.4 package, versions <7.4.3-4ubuntu2.9


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.44% (76th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-UBUNTU2004-PHP74-2406770
  • published18 Feb 2022
  • disclosed27 Feb 2022

Introduced: 18 Feb 2022

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

How to fix?

Upgrade Ubuntu:20.04 php7.4 to version 7.4.3-4ubuntu2.9 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream php7.4 package and not the php7.4 package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 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