Double Free in Cisco Adaptive Security Appliance (Asa) Software
CVE-2025-20134
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.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (34.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Cisco Adaptive Security Appliance (Asa) Software — versions 9.12.4.39, 9.12.4.40, 9.14.4.6
- Cisco Firepower Threat Defense Software — versions 6.6.5.2, 6.4.0.15, 6.6.7
Weakness classification (CWE)
Public proof-of-concept exploits
References
Frequently asked questions
- What is CVE-2025-20134?
- CVE-2025-20134 is a high-severity vulnerability in Cisco Adaptive Security Appliance (Asa) Software, classified under Double Free. CVSS score: 8.6/10. Published 2025-08-14.
- How severe is CVE-2025-20134?
- High severity. CVSS v3 base score is 8.6 out of 10.
- Is CVE-2025-20134 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.