SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-53634

With a slow loris attack, an attacker could cause Denial of Service (DoS).

HIGH 8.7EPSS 0.46%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0
8.7 HIGHCVSS: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/M
EPSS
0.46% probability · 39th percentile
CISA KEV
Not listed
Weakness
CWE-770
Affected
ctfer-io/chall-manager
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.