CVE-2025-63655
Memory Safety in Monkey-Project Monkey ≤ 1.8.5
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-63655 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Monkey-Project Monkey. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — 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.
A NULL pointer dereference vulnerability exists in the mk_http_range_parse function located in mk_server/mk_http.c of the Monkey web server at commit f37e984. Tracked as CVE-2025-63655 and assigned CWE-476, the flaw is reachable over the network and carries a CVSS 3.1 score of 7.5, reflecting high impact to availability with no requirements for authentication or user interaction.
An unauthenticated remote attacker can trigger the defect by sending a crafted HTTP request containing a malicious Range header, causing the server process to dereference a NULL pointer and terminate, resulting in a denial-of-service condition.
Public references to the issue are available in a security advisory and the project's issue tracker, though no specific mitigation steps or patch details are provided in the current disclosure. The associated EPSS score remains low and unchanged at 0.0129, indicating limited observed exploitation interest to date.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206525
Vulnerability Data
A NULL pointer dereference in the mk_http_range_parse function (mk_server/mk_http.c) of monkey commit f37e984 allows attackers to cause a Denial of Service (DoS) via sending a crafted HTTP request to the server.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.
Documented development standards and tools can enforce null-safety rules and safe pointer usage.
Engineering principles can mandate defensive coding such as explicit null checks before dereference.
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.
Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.
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.
Security testing can detect NULL dereference defects before release.
Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.
Application security requirements can specify input validation and pointer-safety rules.
Secure architecture principles encourage defensive design that avoids unsafe pointer use.
Secure coding standards directly require NULL-pointer checks and safe dereference patterns.