CVE-2025-20253 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
Remote unauthenticated attackers can cause device reloads via crafted IKEv2 packets, impacting Cisco IOS, ASA, and FTD devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-20253?
CVE-2025-20253 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance (ASA) Software, published on 14 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources and could cause the device to reload.
Weakness: CWE-835
Which versions are affected by CVE-2025-20253?
How do I fix CVE-2025-20253?
No fix has been published for CVE-2025-20253 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-20253 being exploited?
There is no known exploitation of CVE-2025-20253 in the wild and no public exploit code.
Sources
Also known as GHSA-m842-hm2c-8xm2.