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Adaptive Security Appliance Software CVE-2024-20331

MEDIUM
Use of Insufficiently Random Values (CWE-330)
2024-10-23 psirt@cisco.com
5.9
CVSS 3.1 · NVD
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Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A04:2025 - Cryptographic Failures
ASVS 5.0
V11 - Cryptography Cryptographic random values
Impact

CVSS score of 5.9 (MEDIUM). Attack characteristics: network attack vector, high complexity, no privileges required, no user interaction not required.

Exploit ScenarioDerived

This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the medium-severity affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.6% exploitation probability (EPSS)

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AnalysisAI

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. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

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Technical ContextAI · show details

This vulnerability is classified under CWE-330. 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. Affected products include: Cisco Adaptive Security Appliance Software, Cisco Firepower Threat Defense Software.

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Severity by source

NVD PRIMARY 5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionNVD

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.

Threat Intelligence Overview

EPSS Score
0.6%
Top 53% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.6%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

31
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +30
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)NVD

cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1.5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1.7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.8:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.14:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.15:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.17:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.20:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.24:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.26:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.28:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.33:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.35:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.38:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.45:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.8:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.11:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.14:*:*:*:*:*:*:*
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