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 se...

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

8.7/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.44%

35.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

Affected Software

Vendor	Product	Versions
Ctfer-Io	Chall-Manager	< 0.1.4

References

Timeline

Published: Jul 10, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is 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.

How severe is CVE-2025-53634?

CVE-2025-53634 has a CVSS score of 8.7/10 (HIGH severity). The EPSS model estimates a 0.44% probability of exploitation in the next 30 days.

How do I fix CVE-2025-53634?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.