Resource exhaustion in Ctfer-Io Chall-Manager
CVE-2025-53634
Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. The HTTP Gateway processes headers, but with no timeout set. With a slow loris attack, an attacker could cause Denial of Service (DoS). 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 1385bd8 and shipped in v0.1.4.
EPSS: 0.004 (37.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Ctfer-io Chall-manager — versions < 0.1.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2025-53634?
- CVE-2025-53634 is a high-severity vulnerability in Ctfer-Io Chall-Manager, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2025-07-10.
- How severe is CVE-2025-53634?
- High severity. CVSS v3 base score is 7.5 out of 10.