CVE-2024-20260 Denial of service in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Unauthenticated remote attackers can cause a denial of service by exhausting system memory through excessive SSL/TLS connections on Cisco 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-2024-20260?
CVE-2024-20260 is a high-severity denial of service vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, published on 23 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Update for September 16, 2026: The original 1.0 version of this advisory was specific to the Cisco Adaptive Security Virtual Appliance (ASAv) and Cisco Secure Firewall Threat Defense Virtual (FTDv) models. However, it was later found that this vulnerability affects all Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software platforms. A vulnerability in the VPN and management web servers of the Cisco Secure Firewall ASA Software and Cisco Secure FTD Software platforms could allow an unauthenticated, remote attacker to cause an affected device to run out of system memory or buffer blocks, which in turn could cause SSL VPN connection processing to slow down and eventually cease altogether. This vulnerability is due to a lack of proper memory management for new incoming SSL/TLS connections. An attacker could exploit this vulnerability by sending a large number of new incoming SSL/TLS connections to the targeted device. A successful exploit could allow the attacker to deplete system memory or buffers, resulting in a denial of service (DoS) condition. The memory or buffers could be reclaimed slowly if the attack traffic is stopped, but a manual reload may be required to restore operations quickly.
Weakness: CWE-789
Which versions are affected by CVE-2024-20260?
How do I fix CVE-2024-20260?
No fix has been published for CVE-2024-20260 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-2024-20260 being exploited?
There is no known exploitation of CVE-2024-20260 in the wild and no public exploit code.
Sources
Also known as GHSA-27g3-cp2g-22pw.