Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2023-36661 is a high-severity SSRF (CWE-918) vulnerability in Debian Debian Linux. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 14% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
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-2023-36661 is a server-side request forgery vulnerability in Shibboleth XMLTooling versions prior to 3.2.4. The flaw resides in the handling of KeyInfo elements within XML signatures and affects components used by OpenSAML and the Shibboleth Service Provider; an example fixed release is Shibboleth SP 3.4.1.3 on Windows. The issue is tracked as CWE-918 and carries a CVSS 3.1 score of 7.5.
Unauthenticated remote attackers can supply a crafted KeyInfo element to induce the affected service to issue arbitrary outbound requests. Successful exploitation can impair availability of the targeted system or related infrastructure without requiring user interaction or credentials.
Public advisories from the Shibboleth project and Debian (DSA-5432) recommend upgrading XMLTooling to 3.2.4 or later and applying the corresponding Service Provider updates. The EPSS score for this CVE rose from a low baseline to a peak of 0.6067 with a current value of 0.5241, indicating that exploitation interest increased after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-40605
Vulnerability Data
Shibboleth XMLTooling before 3.2.4, as used in OpenSAML and Shibboleth Service Provider, allows SSRF via a crafted KeyInfo element. (This is fixed in, for example, Shibboleth Service Provider 3.4.1.3 on Windows.)
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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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 attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.
Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.
Validates server-side URLs and resource references to block SSRF attempts.
Detects server-side request forgery through monitoring of unexpected outbound connections.
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 development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
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.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.