CVE-2025-20244
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access VPN Web Server Denial of Service Vulnerability
Vexday Risk Score
21Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 7.7EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
14 Aug 2025Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Affected products
Cisco · Cisco Adaptive Security Appliance (ASA) SoftwareCisco · Cisco Firepower Threat Defense SoftwareWant to know if your infrastructure is exposed to this?
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