CVE-2025-20135

Medium

Description

A vulnerability in the DHCP client functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to exhaust available memory. This vulnerability is due to improper validation of incoming DHCP packets. An attacker could exploit this vulnerability by repeatedly sending crafted DHCPv4 packets to an affected device. A successful exploit could allow the attacker to exhaust available memory, which would affect availability of services and prevent new processes from starting, resulting in a Denial of Service (DoS) condition that would require a manual reboot. Note: On Cisco Secure FTD Software, this vulnerability does not affect management interfaces.

SeverityMedium
CVSS4.3
Exploit probability—
ProductCisco Adaptive Security Appliance (ASA) Software
PublishedAug 14, 2025
First seenAug 14, 2025
Weakness typeCWE-401CWE-401

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, 9.15.1.1, 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—

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