DoS via Remote Access SSL VPN Auth in Cisco ASA/FTD
CVE-2024-20493 Published on October 23, 2024

A vulnerability in the login 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 deny further VPN user authentications for several minutes, resulting in a temporary denial of service (DoS) condition. This vulnerability is due to ineffective handling of memory resources during the authentication process. An attacker could exploit this vulnerability by sending crafted packets, which could cause resource exhaustion of the authentication process. A successful exploit could allow the attacker to deny authentication for Remote Access SSL VPN users for several minutes, resulting in a temporary DoS condition.

NVD

Vulnerability Analysis

CVE-2024-20493 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
LOW

Weakness Type

Missing Release of Resource after Effective Lifetime

The software does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. When a resource is not released after use, it can allow attackers to cause a denial of service by causing the allocation of resources without triggering their release. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.


Products Associated with CVE-2024-20493

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2024-20493 are published in these products:

Cisco Firepower Threat Defense Software
 
Cisco Adaptive Security Appliance Software
 

Affected Versions

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

Exploit Probability

EPSS
0.12%
Percentile
31.01%

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.