Raw vector
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:XSummary
CVE-2025-53633 is a high-severity Amplification (CWE-405) vulnerability in Ctfer-Io Chall-Manager. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-53633 affects Chall-Manager, a platform-agnostic system designed to start challenges on demand for players. The vulnerability arises during the decoding of scenarios, which are zip archives, where the size of the decoded content is not checked. This flaw enables the decompression of zip bombs, leading to asymmetric resource consumption as described by CWE-405. The issue carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.
The vulnerability can be exploited by unauthenticated attackers with network access to the Chall-Manager instance, requiring no authorization. Successful exploitation allows attackers to trigger massive resource exhaustion through specially crafted zip bombs, potentially resulting in high-impact denial of service, as well as impacts to confidentiality, integrity, and availability per the CVSS vector. Although the Chall-Manager documentation highly recommends deploying the system deep within infrastructure to prevent direct user access due to its extensive capabilities, exposure could still enable remote exploitation.
Mitigation is available through a patch implemented in commit 14042aa, which has been shipped in version v0.1.4 of Chall-Manager. Security practitioners should update to this version promptly. Additional details are provided in the project's security advisory (GHSA-r7fm-3pqm-ww5w), the patch commit, and the release notes.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-21056
Vulnerability Data
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 6 hardening rules · 3 OS baselines
—
Mitigating Controls (NIST 800-53 r5) AI
SC-5 directly requires mechanisms to limit the effects of asymmetric resource exhaustion attacks such as amplification DoS.
SC-6 enforces resource quotas and priority allocation that reduce the impact of unauthenticated or low-effort resource requests.
Least-functionality disables unnecessary services or features that could be leveraged for amplification.
SC-7 boundary controls can filter or rate-limit traffic patterns that enable amplification without equivalent client work.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Resilience mechanisms such as rate limiting and load balancing directly constrain asymmetric resource use.
Capacity planning and monitoring maintain availability headroom against amplification attacks.
Network monitoring detects amplification traffic patterns but does not itself limit asymmetric consumption.
Runtime resource monitoring can surface excessive consumption yet does not enforce authorization or work proofs.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Stress-testing and demand-reduction tactics (e.g., bandwidth throttling) blunt amplification vectors that would otherwise let an attacker multiply resource consumption through a single request.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405
- V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
Oracle Linux 9 (2 rules)
- V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
- V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405
RHEL 8 (2 rules)
- V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
- V-244525 RHEL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405