Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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-2024-20331 is a medium-severity Use of Insufficiently Random Values (CWE-330) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 6.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked in the top 49% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-12 (Cryptographic Key Establishment and Management) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-18046
Vulnerability Data
A vulnerability in the session authentication functionality of the Remote Access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to prevent users from authenticating. This…
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vulnerability is due to insufficient entropy in the authentication process. An attacker could exploit this vulnerability by determining the handle of an authenticating user and using it to terminate their authentication session. A successful exploit could allow the attacker to force a user to restart the authentication process, preventing a legitimate user from establishing remote access VPN sessions.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 6 hardening rules · 3 OS baselines
V11.3.4
Mitigating Controls (NIST 800-53 r5) AI
SC-12 requires proper cryptographic key establishment and management, which structurally mandates use of sufficient randomness for key generation.
Security engineering principles can include selection of strong entropy sources during design.
SC-13 requires selection and implementation of approved cryptographic algorithms and methods, which inherently depend on and enforce sufficiently random values.
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.
Password-strength policies implicitly require sufficient entropy, but the control addresses authentication rather than algorithmic randomness.
Proper encryption for data-at-rest requires sufficient entropy for keys/nonces; eliminating the weakness therefore supports but does not fully realize the control.
Cryptographic protection of data-in-transit depends on adequate entropy; the weakness directly undermines the control's effectiveness.
Secure SDLC practices explicitly include vetted RNG and entropy sources, directly preventing this weakness while covering many other development concerns.
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.
Cryptographic controls require use of approved, sufficiently random values for keys and nonces.
Secure SDLC processes include verification steps that can catch insufficient randomness but do not directly specify RNG requirements.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. blocks CWE-331
- V-248563 The OL 8 SSH server must be configured to use strong entropy. blocks CWE-331
RHEL 7 (1 rule)
- V-204497 The Red Hat Enterprise Linux operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. blocks CWE-331
RHEL 8 (1 rule)
- V-230223 RHEL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. blocks CWE-331