Kimai is a web-based multi-user time-tracking application. Versions prior to 2.1.0 are vulnerable to a Server-Side Template Injection (SSTI) which can be escalated to Remote Code Execution (RCE). The vulnerability arises when a malicious user uploads a specially crafted Twig file, exploiting the software's PDF and HTML rendering functionalities. Version 2.1.0 enables security measures for custom Twig templates.
https://github.com/kimai/kimai/security/advisories/GHSA-fjhg-96cp-6fcw
https://github.com/kimai/kimai/commit/38e37f1c2e91e1acb221ec5c13f11b735bd50ae4