CVE-2025-20244

High

Description

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow a remote attacker that is authenticated as a VPN user to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header field value. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause a DoS condition, which would cause the affected device to reload.

SeverityHigh
CVSS7.7
Exploit probability—
ProductCisco Adaptive Security Appliance (ASA) Software
PublishedAug 14, 2025
First seenAug 14, 2025
Weakness typeCWE-1287CWE-1287

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Cisco Cisco Adaptive Security Appliance (ASA) Software9.12.3, 9.8.3, 9.12.1, 9.8.1, 9.12.2, 9.8.2.45, 9.8.2, 9.8.4, 9.14.1, 9.12.4, 9.8.2.26, 9.8.2.24, 9.8.2.15, 9.8.2.14, 9.8.2.35, 9.8.2.20, 9.8.2.8, 9.8.2.17, 9.8.2.28, 9.8.2.33, 9.8.2.38, 9.8.4.25, 9.12.3.2, 9.12.3.7, 9.8.3.18, 9.8.3.14, 9.8.4.15, 9.8.4.8, 9.8.1.7, 9.8.3.29, 9.14.1.10, 9.12.2.5, 9.8.4.22, 9.12.3.12, 9.8.4.7, 9.8.4.17, 9.8.3.16, 9.8.4.20, 9.8.3.11, 9.12.1.3, 9.8.4.3, 9.12.2.4, 9.8.4.12, 9.12.1.2, 9.8.3.26, 9.8.1.5, 9.12.2.9, 9.12.3.9, 9.8.3.21, 9.8.4.10, 9.12.2.1, 9.12.4.2, 9.14.1.6, 9.8.3.8, 9.14.1.15, 9.14.1.19, 9.8.4.26, 9.12.4.4, 9.14.1.30, 9.8.4.29, 9.12.4.7, 9.14.2, 9.12.4.8, 9.8.4.32, 9.12.4.10, 9.14.2.4, 9.14.2.8, 9.12.4.13, 9.8.4.33, 9.14.2.13, 9.8.4.34, 9.12.4.18, 9.8.4.35, 9.14.2.15, 9.12.4.24, 9.16.1, 9.8.4.39, 9.14.3, 9.12.4.26, 9.16.1.28, 9.14.3.1, 9.12.4.29, 9.14.3.9, 9.16.2, 9.12.4.30, 9.16.2.3, 9.8.4.40, 9.14.3.11, 9.12.4.35, 9.8.4.41, 9.14.3.13, 9.16.2.7, 9.12.4.37, 9.14.3.15, 9.17.1, 9.16.2.11, 9.14.3.18, 9.16.2.13, 9.12.4.39, 9.12.4.38, 9.8.4.43, 9.14.4, 9.16.2.14, 9.17.1.7, 9.12.4.40, 9.16.3.3, 9.14.4.6, 9.16.3, 9.16.3.14, 9.17.1.9, 9.14.4.7, 9.12.4.41, 9.17.1.10, 9.8.4.44, 9.18.1, 9.12.4.47, 9.14.4.12, 9.16.3.15, 9.18.1.3, 9.17.1.11, 9.12.4.48, 9.14.4.13, 9.18.2, 9.16.3.19, 9.17.1.13, 9.12.4.50, 9.14.4.14, 9.17.1.15, 9.8.4.45, 9.12.4.52, 9.14.4.15, 9.16.3.23, 9.18.2.5, 9.16.4, 9.12.4.54, 9.14.4.17, 9.8.4.46, 9.17.1.20, 9.18.2.7, 9.19.1, 9.16.4.9, 9.12.4.55, 9.18.2.8, 9.14.4.22, 9.16.4.14, 9.8.4.48, 9.18.3, 9.19.1.5, 9.14.4.23, 9.12.4.56, 9.16.4.18, 9.17.1.30, 9.19.1.9, 9.18.3.39, 9.16.4.19, 9.12.4.58, 9.19.1.12, 9.18.3.46, 9.16.4.27, 9.19.1.18, 9.18.3.53, 9.18.3.55, 9.16.4.38, 9.17.1.33, 9.12.4.62, 9.16.4.39, 9.18.3.56, 9.20.1, 9.16.4.42, 9.19.1.22, 9.18.4, 9.20.1.5, 9.18.4.5, 9.19.1.24, 9.16.4.48, 9.18.4.8, 9.20.2, 9.19.1.27, 9.12.4.65, 9.16.4.55, 9.18.4.22, 9.20.2.10, 9.16.4.57, 9.19.1.28, 9.17.1.39, 9.12.4.67, 9.14.4.24, 9.18.4.24, 9.20.2.21, 9.16.4.61, 9.19.1.31, 9.18.4.29, 9.20.2.22, 9.16.4.62, 9.18.4.34, 9.20.3, 9.16.4.67, 9.16.4.70, 9.18.4.40, 9.22.1.1—

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