{"id":85905,"date":"2025-11-27T21:32:24","date_gmt":"2025-11-27T21:32:24","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-20244-denial-of-service-vulnerability-in-cisco-secure-firewall","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20244-denial-of-service-vulnerability-in-cisco-secure-firewall\/","title":{"rendered":"CVE-2025-20244: Denial of Service Vulnerability in Cisco Secure Firewall<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

This report discusses a critical vulnerability, CVE-2025-20244, that poses a significant threat to the Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability could allow a remote attacker, authenticated as a VPN user, to cause an unexpected system reload and subsequently a denial of service (DoS) condition.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-20244
\nSeverity: High (7.7 CVSS Score)
\nAttack Vector: Network
\nPrivileges Required: Low (Authenticated VPN User)
\nUser Interaction: None
\nImpact: Potential system compromise or data leakage, denial of service condition<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | All versions prior to patch
\nCisco Secure Firewall Threat Defense (FTD) Software | All versions prior to patch<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability CVE-2025-20244 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 cause a DoS condition, which would cause the affected device to reload.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Below is a conceptual example of how the vulnerability might be exploited. This is a crafted HTTP request that could potentially trigger the vulnerability:<\/p>\n

POST \/targeted\/vpn\/service HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\nVPN-User: authenticated user\n{ \"malicious_payload\": \"crafted HTTP header field value causing error\" }<\/code><\/pre>\n
Please note that the above is a simplified representation and actual exploitation may require more sophisticated techniques.<\/p>\n
Mitigation<\/strong><\/p>\n
To mitigate this vulnerability, it is recommended to apply the vendor patch as soon as it becomes available. Until then, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) may serve as temporary mitigation. Regularly updating all software and maintaining vigilance for any unusual network activity can also provide additional layers of security.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview This report discusses a critical vulnerability, CVE-2025-20244, that poses a significant threat to the Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability could allow a remote attacker, authenticated as a VPN user, to cause an unexpected system reload and subsequently a denial of service […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-85905","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t