CVE-2024-20331: Cisco ASA/FTD Auth Entropy Leak Blocks VPN
CVE-2024-20331 Published on October 23, 2024

Cisco Adaptive Security Appliance and Firepower Threat Defense Software VPN Authentication DoS Vulnerability
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.

NVD

Vulnerability Analysis

CVE-2024-20331 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Use of Insufficiently Random Values

The software uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. When software generates predictable values in a context requiring unpredictability, it may be possible for an attacker to guess the next value that will be generated, and use this guess to impersonate another user or access sensitive information.


Products Associated with CVE-2024-20331

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2024-20331 are published in these products:

Cisco Adaptive Security Appliance Software
 
Cisco Firepower Threat Defense Software
 
Cisco Adaptive Security Appliance
 

Affected Versions

Cisco Adaptive Security Appliance (ASA) Software: Cisco Firepower Threat Defense Software:

Exploit Probability

EPSS
0.95%
Percentile
76.03%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.