Cisco ASA SSH Server DoS via crafted SSH messages
CVE-2024-20526 Published on October 23, 2024
A vulnerability in the SSH server of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition for the SSH server of an affected device. This vulnerability is due to a logic error when an SSH session is established. An attacker could exploit this vulnerability by sending crafted SSH messages to an affected device. A successful exploit could allow the attacker to exhaust available SSH resources on the affected device so that new SSH connections to the device are denied, resulting in a DoS condition. Existing SSH connections to the device would continue to function normally. The device must be rebooted manually to recover. However, user traffic would not be impacted and could be managed using a remote application such as Cisco Adaptive Security Device Manager (ASDM).
Vulnerability Analysis
CVE-2024-20526 is exploitable 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.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2024-20526 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2024-20526
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Affected Versions
Cisco Adaptive Security Appliance (ASA) Software:- Version 9.16.4.67 is affected.
- Version 9.16.4.70 is affected.
- Version 9.18.4.40 is affected.
- Version 9.20.3 is affected.
- Version 9.16.4.67 is affected.
- Version 9.16.4.70 is affected.
- Version 9.18.4.40 is affected.
- Version 9.20.3 is affected.
Exploit Probability
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.