SB2025081957 - Remote denial of service in Cisco ASA and FTD



SB2025081957 - Remote denial of service in Cisco ASA and FTD

Published: August 19, 2025

Security Bulletin ID SB2025081957
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Double free (CVE-ID: CVE-2025-20134)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when parsing SSL/TLS certificates. A remote attacker can send specially crafted DNS packets that match a static Network Address Translation (NAT) rule with DNS inspection enabled through an affected device, trigger a double free error and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.