CVE-2025-20136 | Cisco Secure Firewall - Adaptive Security Appliance (ASA) Software Operational Intel

Executive Risk Summary

"A vulnerability in the 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 an infinite loop condition that occurs when a Cisco Secure ASA or Cisco Secure FTD device processes DNS packets with DNS inspection enabled and the device is configured for NAT44, NAT64, or NAT46."

Operational Audit Arsenal

Target Type Firmware Image

Target Asset Cisco Secure Firewall ASA/FTD Software

Standard Path Global Firmware

Manual Verification Required

This is a non-Windows asset (Cisco). Use the target asset details and official path provided above to verify your current version against the official vendor advisories listed below.

Patch Impact Forecast

Reboot Required Likely

High

Internal Work Notes

CVE-2025-20136: Cisco Secure Firewall ASA/FTD Software vulnerability allowing remote DoS attacks via crafted DNS packets, requiring firmware update to resolve.

Technical Intelligence & Operational Utilities • Delivered Weekly

Intelligence Sources

Official Advisoryhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-nat-dns-dos-bqhynHTM

Related Cisco Threats

CVE-2026-20079 CVSS 10

Secure Firewall Management Center (FMC) Software

CVE-2026-20127 CVSS 10

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CVE-2025-20188 CVSS 10

Cisco IOS XE - Wireless LAN Controllers

Data compiled from NVD, MSRC, and CISA KEV Catalog. Intelligence synthesized via AI. Scripts provided for diagnostic purposes under MIT License.