A PHP security update has been released for Ubuntu Linux 14.04 ESM, 16.04 ESM, 18.04 LTS, 20.04 LTS, 21.04, and 21.10.

USN-5125-1: PHP vulnerability

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Ubuntu Security Notice USN-5125-1
October 27, 2021

php5, php7.0, php7.2, php7.4, php8.0 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.10
- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

PHP-PFM in PHP could be made to run program as an administrator
if it received specially crafted input.

Software Description:
- php8.0: HTML-embedded scripting language interpreter
- php7.4: HTML-embedded scripting language interpreter
- php7.2: HTML-embedded scripting language interpreter
- php7.0: HTML-embedded scripting language interpreter
- php5: HTML-embedded scripting language interpreter

Details:

It was discovered that PHP-FPM in PHP incorrectly handled certain inputs.
An attacker could possibly use this issue to cause a crash or execute
arbitrary code.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 21.10:
php8.0-fpm 8.0.8-1ubuntu0.1

Ubuntu 21.04:
php7.4-fpm 7.4.16-1ubuntu2.2

Ubuntu 20.04 LTS:
php7.4-fpm 7.4.3-4ubuntu2.7

Ubuntu 18.04 LTS:
php7.2-fpm 7.2.24-0ubuntu0.18.04.10

Ubuntu 16.04 ESM:
php7.0-fpm 7.0.33-0ubuntu0.16.04.16+esm2

Ubuntu 14.04 ESM:
php5-fpm 5.5.9+dfsg-1ubuntu4.29+esm15

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5125-1
CVE-2021-21703

Package Information:
  https://launchpad.net/ubuntu/+source/php8.0/8.0.8-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/php7.4/7.4.16-1ubuntu2.2
  https://launchpad.net/ubuntu/+source/php7.4/7.4.3-4ubuntu2.7
  https://launchpad.net/ubuntu/+source/php7.2/7.2.24-0ubuntu0.18.04.10