Cisco ASA/Firepower Threat Defense IKEv2 memory leak

Summaryinfo

A vulnerability was found in Cisco ASA and Firepower Threat Defense. It has been rated as problematic. Affected is an unknown function of the component IKEv2 Handler. Performing a manipulation results in memory leak. This vulnerability is reported as CVE-2025-20252. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Cisco ASA and Firepower Threat Defense (version unknown). This affects an unknown function of the component IKEv2 Handler. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco 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 improper parsing of IKEv2 packets. An attacker could exploit this vulnerability by sending a continuous stream of crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to partially exhaust system memory, causing system instability like being unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from this condition.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is uniquely identified as CVE-2025-20252 since 10/10/2024. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/17/2025). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1838). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Cisco IOS
• Cisco IOS XE
• Cisco ASA (Adaptive Security Appliance)
• Cisco Secure Firewall Threat Defense

Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• ASA
• Firepower Threat Defense

License

• commercial

Website

• Vendor: https://www.cisco.com/

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