8.6

CVE-2025-20134: cisco cisco adaptive security appliance (asa) software Double Free

CVSS: 8.6v3.1HighDeferred
Published 14-08-2025Last modified 19-08-2025
Open JSON

Vulnerability summary

CVE-2025-20134 is a high (CVSS 8.6) Double Free vulnerability in cisco cisco adaptive security appliance (asa) software. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.6% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-08-2025
    PublishedVulnerability first disclosed.
  2. 19-08-2025
    Last modifiedVulnerability information updated.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.02 pp

From 0.40% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco2 products
  • cisco adaptive security appliance (asa) software9.12.4.39 | 9.12.4.40 | 9.14.4.6 | 9.14.4.7 | 9.12.4.41 | 9.12.4.47 | 9.14.4.12 | 9.12.4.48 | 9.14.4.13 | 9.12.4.50 | 9.14.4.14 | 9.12.4.52 | 9.14.4.15 | 9.12.4.54 | 9.14.4.17 | 9.12.4.55 | 9.14.4.22 | 9.14.4.23 | 9.12.4.56 | 9.12.4.58 | 9.12.4.62 | 9.12.4.65 | 9.12.4.67 | 9.14.4.24
  • cisco firepower threat defense software6.6.5.2 | 6.4.0.15 | 6.6.7 | 6.4.0.16 | 6.6.7.1 | 6.4.0.17 | 6.6.7.2 | 6.4.0.18

1 vendor · 2 products

References

1 links