Cisco ASA/FTD VPN Websrv DoS via HTTP Header Parsing
CVE-2024-20353 Published on April 24, 2024

A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

NVD

Known Exploited Vulnerability

This Cisco ASA and FTD Denial of Service Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an infinite loop vulnerability that can lead to remote denial of service condition.

The following remediation steps are recommended / required by May 1, 2024: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vulnerability Analysis

CVE-2024-20353 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. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. 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:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

What is an Infinite Loop Vulnerability?

The program contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. If the loop can be influenced by an attacker, this weakness could allow attackers to consume excessive resources such as CPU or memory.

CVE-2024-20353 has been classified to as an Infinite Loop vulnerability or weakness.


Products Associated with CVE-2024-20353

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2024-20353 are published in these products:

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

Affected Versions

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

Exploit Probability

EPSS
19.54%
Percentile
95.27%

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.