CVE-2023-36661
Published: 25 June 2023
Summary
CVE-2023-36661 is a high-severity SSRF (CWE-918) vulnerability in Debian Debian Linux. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 2.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-40605
Vulnerability details
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
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
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 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.