{"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":"-0001-11-30T06:00:00","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":"<strong>CVE-2025-20244: Denial of Service Vulnerability in Cisco Secure Firewall<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>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<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-20244<br \/>\nSeverity: High (7.7 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: Low (Authenticated VPN User)<br \/>\nUser Interaction: None<br \/>\nImpact: Potential system compromise or data leakage, denial of service condition<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-458972372\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p>Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | All versions prior to patch<br \/>\nCisco Secure Firewall Threat Defense (FTD) Software | All versions prior to patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>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<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-299750996\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>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<pre><code class=\"\" data-line=\"\">POST \/targeted\/vpn\/service HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\nVPN-User: authenticated user\n{ &quot;malicious_payload&quot;: &quot;crafted HTTP header field value causing error&quot; }<\/code><\/pre>\n<p>Please note that the above is a simplified representation and actual exploitation may require more sophisticated techniques.<\/p>\n<p><strong>Mitigation<\/strong><\/p>\n<p>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":"<p>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 [&hellip;]<\/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,"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":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85905","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=85905"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85905\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=85905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=85905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=85905"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=85905"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=85905"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=85905"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=85905"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=85905"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=85905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}