CVE-2025-20239: cisco cisco adaptive security appliance (asa) software

Vulnerability summary

CVE-2025-20239 is a high (CVSS 8.6) vulnerability in cisco cisco adaptive security appliance (asa) software. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 48.5% of scored vulnerabilities.

Timeline

1. 14-08-2025
   PublishedVulnerability first disclosed.
2. 14-08-2025
   Last modifiedVulnerability information updated.

Description

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition. This vulnerability is due to a lack of proper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit could allow the attacker to partially exhaust system memory, causing system instability such as being unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from this condition.

• CWE-401Missing Release of Memory after Effective LifetimeThe product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.