CVE-2025-53632: Chall-Manager's scenario decoding process does not check for zip slips

Vulnerability summary

CVE-2025-53632 is a critical (CVSS 9.1) vulnerability in ctfer-io chall-manager. EPSS estimates a 0.82% chance of exploitation in the next 30 days, higher than 57.3% of scored vulnerabilities.

Timeline

1. 10-07-2025
   PublishedVulnerability first disclosed.
2. 10-07-2025
   Last modifiedVulnerability information updated.

Description

Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. When decoding a scenario (i.e. a zip archive), the path of the file to write is not checked, potentially leading to zip slips. Exploitation does not require authentication nor authorization, so anyone can exploit it. It should nonetheless not be exploitable as it is highly recommended to bury Chall-Manager deep within the infrastructure due to its large capabilities, so no users could reach the system. Patch has been implemented by commit 47d188f and shipped in v0.1.4.

• CWE-22Improper Limitation of a Pathname to a Restricted DirectoryThe product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.