Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:NSummary
CVE-2024-20531 is a medium-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Cisco Identity Services Engine. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29th 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 AC-4 (Information Flow Enforcement) and CM-6 (Configuration Settings) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-18246
Vulnerability Data
A vulnerability in the API of Cisco ISE could allow an authenticated, remote attacker to read arbitrary files on the underlying operating system of an affected device and conduct a server-side request forgery (SSRF) attack through an affected device. To…
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exploit this vulnerability, the attacker would need valid Super Admin credentials. This vulnerability is due to improper handling of XML External Entity (XXE) entries when parsing XML input. An attacker could exploit this vulnerability by sending a crafted API request to an affected device. A successful exploit could allow the attacker to read arbitrary files on the underlying operating system or conduct an SSRF attack through the affected device.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.5.1V15.3.2V1.3.6V1.5.3
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Secure configuration settings can disable external entity processing in XML parsers.
Developer testing can discover XXE flaws through targeted XML parsing tests.
Input validation can reject or sanitize XML containing external entity references.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
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.
Hardened XML parser configurations directly disable external entity resolution.
Secure SDLC practices include input validation and safe XML parser configuration that prevent XXE.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.
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 in development catches XXE via static analysis and dynamic XML fuzzing.
Vulnerability management identifies and patches XML libraries with unsafe default entity settings.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.
Secure development life cycle mandates input validation and entity handling that directly prevents XXE.
Application security requirements explicitly call for disabling external entity processing in XML parsers.
Secure architecture principles include safe parser configuration that mitigates external entity risks.