Vulnerability in Ctfer-Io Chall-Manager

CVE-2025-53633

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 size of the decoded content is not checked, potentially leading to zip bombs decompression. 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 14042aa and shipped in v0.1.4.

EPSS: 0.005 (38.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-53633?
CVE-2025-53633 is a critical-severity vulnerability in Ctfer-Io Chall-Manager, classified under Asymmetric Resource Consumption (Amplification). CVSS score: 9.8/10. Published 2025-07-10.
How severe is CVE-2025-53633?
Critical severity. CVSS v3 base score is 9.8 out of 10.