CVE-2025-20243 — Infinite Loop in Cisco Adaptive Security Appliance Software

CWE-835 — Infinite Loop CWE-401 — Missing Release of Memory after Effective Lifetime4 documents4 sources

Severity

8.6HIGHNVD

EPSS

0.0%

top 93.53%

CISA KEV

Not in KEV

Exploit

No known exploits

Affected products

Cisco Adaptive Security Appliance Software Cisco Firepower Threat Defense Software

Timeline

PublishedAug 14

Description

A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to improper validation of user-supplied input on an interface with VPN web services. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on an affected device. A successful exploit cou…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitability: 3.9 | Impact: 4.0

Affected Packages2 packages

▶CVEListV5cisco/cisco_firepower_threat_defense_software94 versions+93

▶CVEListV5cisco/cisco_adaptive_security_appliance_software220 versions+219

🔴Vulnerability Details

GHSA

GHSA-9qx2-hwjm-5mww: A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, re↗2025-08-14

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CVEList

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability↗2025-08-14

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📋Vendor Advisories

Cisco

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerabilities↗2025-08-14

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