{"id":64274,"date":"2025-08-23T23:10:59","date_gmt":"2025-08-23T23:10:59","guid":{"rendered":""},"modified":"2025-08-31T18:37:28","modified_gmt":"2025-09-01T00:37:28","slug":"cve-2025-20222-critical-dos-vulnerability-in-cisco-secure-firewalls","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20222-critical-dos-vulnerability-in-cisco-secure-firewalls\/","title":{"rendered":"CVE-2025-20222: Critical DoS Vulnerability in Cisco Secure Firewalls<\/strong>"},"content":{"rendered":"

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

In the rapidly evolving world of cybersecurity, it is crucial for organizations to stay abreast of vulnerabilities that could potentially compromise their systems. One such security flaw, dubbed CVE-2025-20222, poses a significant threat to entities using Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability has a high potential for system compromise and data<\/a> leakage, making it a matter of grave concern for organizations safeguarding sensitive data.<\/p>\n

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

CVE ID: CVE-2025-20222
\nSeverity: Critical, CVSS score of 8.6
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: A successful exploit could lead to a Denial of Service (DoS) condition, potentially causing system compromise<\/a> or data leakage.<\/p>\n

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

Product | Affected Versions<\/p>\n

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

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

The vulnerability lies in the RADIUS proxy feature for the IPsec VPN feature of Cisco’s Secure<\/a> Firewall software. This feature is susceptible to a flaw in the processing of IPv6 packets. An attacker could exploit this vulnerability by sending malicious IPv6 packets<\/a> over an IPsec VPN connection to the affected device. Upon successful exploitation, the device is forced to reload, resulting in a Denial of Service<\/a> (DoS) condition.<\/p>\n

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

The following is a conceptual representation of how the vulnerability might be exploited. This is not actual exploit code but a simplified example to demonstrate the concept:<\/p>\n

#!\/bin\/bash\n# This is a conceptual script to send malicious IPv6 packets.\nTARGET_IP=\"target.device.ip\"\nVPN_CONNECTION=\"vpn.connection.details\"\n# Establish VPN connection\nestablish_ipsec_vpn_connection $VPN_CONNECTION\n# Craft malicious IPv6 packet\nmalicious_packet=$(craft_ipv6_packet)\n# Send malicious IPv6 packet to target over VPN connection\nsend_packet_over_vpn $TARGET_IP $malicious_packet<\/code><\/pre>\n
Please note that the mitigation guidance for this vulnerability is to apply the vendor patch. In the absence of an immediate patch, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview In the rapidly evolving world of cybersecurity, it is crucial for organizations to stay abreast of vulnerabilities that could potentially compromise their systems. One such security flaw, dubbed CVE-2025-20222, poses a significant threat to entities using Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability […]<\/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":[1],"tags":[],"vendor":[96],"product":[],"attack_vector":[87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-64274","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-cisco","attack_vector-dos"],"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