CVE-2025-55214 Information

Aug 19, 2025 cve

Description

Copier library and CLI app for rendering project templates. From 7.1.0 to before 9.9.1 Copier suggests that it’s safe to generate a project from a safe template i.e. one that doesn’t use unsafe features like custom Jinja extensions which would require passing the –UNSAFE–trust flag. As it turns out a safe template can currently write files outside the destination path where a project shall be generated or updated. This is possible when rendering a generated directory structure whose rendered path is either a relative parent path or an absolute path. Constructing such paths is possible using Copier’s builtin pathjoin Jinja filter and its builtin _copier_conf.sep variable which is the platform-native path separator. This way a malicious template author can create a template that overwrites arbitrary files (according to the user’s write permissions) e.g. to cause havoc. This vulnerability is fixed in 9.9.1.

Reference

https://github.com/copier-org/copier/commit/fdbc0167cc22780b497e4db176feaf6f024757d6 https://github.com/copier-org/copier/security/advisories/GHSA-p7q8-grrj-3m8w

CNNVD-202508-2032 (Published: 2025-08-18)

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