Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.42 and 4.0.2, template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string. Users should upgrade to version 3.1.42 or 4.0.2 to receive a patch.
https://www.smarty.net/docs/en/language.function.math.tpl
https://www.debian.org/security/2022/dsa-5151
https://security.gentoo.org/glsa/202209-09
https://packagist.org/packages/smarty/smarty
https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
https://github.com/smarty-php/smarty/releases/tag/v4.0.2
https://github.com/smarty-php/smarty/releases/tag/v3.1.42
https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71