CVE-2025-63721
Published: 08 December 2025
Summary
CVE-2025-63721 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Hummerrisk Hummerrisk. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 30.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-201789
Vulnerability details
HummerRisk thru v1.5.0 is using a vulnerable Snakeyaml component, allowing attackers with normal user privileges to hit the /rule/add API and thereby achieve RCE and take over the server.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Insecure deserialization vulnerability in SnakeYAML (via /rule/add API) allows normal authenticated users to achieve arbitrary file writes and RCE (e.g., overwriting /etc/crontab), enabling exploitation for privilege escalation and of public-facing web applications.
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Validates or rejects untrusted serialized data before deserialization occurs.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.