What is CVE-2024-20331?

CVE-2024-20331 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Use of Insufficiently Random Values. CVSS score: 6.8/10. Published 2024-10-23.

How severe is CVE-2024-20331?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Is CVE-2024-20331 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Cisco Adaptive Security Appliance Software

CVE-2024-20331

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 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.

Published 2024-10-23 · last modified 2026-08-11.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.3th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Cisco Adaptive Security Appliance Software — versions 9.8.1, 9.8.1.5, 9.8.1.7
Cisco Adaptive Security Appliance (Asa) Software — versions 9.12.3, 9.8.3, 9.12.1
Cisco Firepower Threat Defense Software — versions 6.2.3.14, 6.4.0.1, 6.2.3.7
Cisco Firepower Threat Defense Software — versions 6.2.3, 6.2.3.1, 6.2.3.2
Cisco Secure Firewall Threat Defense — versions 6.2.3, 6.2.3.1, 6.2.3.2

Weakness classification (CWE)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-… (Vendor Advisory)
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-… (Broken Link)
sec.cloudapps.cisco.com/security/center/viewErp.x (Vendor Advisory)

Frequently asked questions

What is CVE-2024-20331?: CVE-2024-20331 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Use of Insufficiently Random Values. CVSS score: 6.8/10. Published 2024-10-23.
How severe is CVE-2024-20331?: Medium severity. CVSS v3 base score is 6.8 out of 10.
Is CVE-2024-20331 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.