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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- EPSS
- 0.42% probability · 36th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-415
- Source
- psirt@cisco.com
EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.