CVE-2025-20363: Cisco Adaptive Security Appliance Software

Critical severity, CVSS 9.0. EPSS: 6.9% chance of exploitation in the next 30 days.

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.

Affected products

  • Cisco Adaptive Security Appliance Software: from 9.12, before 9.12.4.72 (fixed in 9.12.4.72); from 9.14, before 9.14.4.28 (fixed in 9.14.4.28); from 9.16, before 9.16.4.84 (fixed in 9.16.4.84); from 9.17.1, before 9.18.4.57 (fixed in 9.18.4.57); from 9.19.1, before 9.19.1.42 (fixed in 9.19.1.42); from 9.20.1, before 9.20.3.16 (fixed in 9.20.3.16); …
  • Cisco IOS: from 12.2\(15\)b, up to and including 15.9\(3\)m11
  • Cisco IOS XE: from 3.2.0sg, up to and including 17.17.1
  • Cisco IOS XR: version 6.5.1 only; version 6.5.2 only; version 6.5.3 only; version 6.6.2 only; version 6.6.3 only; version 6.6.25 only; …
  • Cisco Secure Firewall Threat Defense: from 7.0.0, before 7.0.8 (fixed in 7.0.8); from 7.1.0, before 7.2.10 (fixed in 7.2.10); from 7.3.0, before 7.4.2.3 (fixed in 7.4.2.3); from 7.7.0, before 7.7.10 (fixed in 7.7.10); version 7.6.0 only

Published 2025-09-25. Last modified 2026-08-11.