Vulnerability · Published Aug 14, 2025 · Assigned by cisco
CVE-2025-20134Cisco Adaptive Security Appliance and Firepower Threat Defense Software SSL/TLS Certificate Denial of Service Vulnerability
High 8.6
In plain English
A high-severity double free in Cisco Adaptive Security Appliance (ASA) Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).
Official description
A vulnerability in the certificate processing of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper parsing of SSL/TLS certificates. An attacker could exploit this vulnerability by sending crafted DNS packets that match a static Network Address Translation (NAT) rule with DNS inspection enabled through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | 9.12.4.399.12.4.409.14.4.69.14.4.79.12.4.419.12.4.479.14.4.129.12.4.48 |
| Cisco | Cisco Firepower Threat Defense Software | 6.6.5.26.4.0.156.6.76.4.0.166.6.7.16.4.0.176.6.7.26.4.0.18 |
Weakness: CWE-415 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H