{"id":64276,"date":"2025-08-24T01:11:35","date_gmt":"2025-08-24T01:11:35","guid":{"rendered":""},"modified":"2025-09-14T11:55:58","modified_gmt":"2025-09-14T17:55:58","slug":"cve-2025-20243-cisco-secure-firewall-asa-software-and-secure-ftd-software-dos-vulnerability","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20243-cisco-secure-firewall-asa-software-and-secure-ftd-software-dos-vulnerability\/","title":{"rendered":"<strong>CVE-2025-20243: Cisco Secure Firewall ASA Software and Secure FTD Software DoS Vulnerability<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>In the world of cybersecurity, any weak link in a system&#8217;s defense can lead to disastrous consequences. This is particularly the case with vulnerabilities like CVE-2025-20243, which predominantly affects Cisco&#8217;s Secure Firewall ASA Software and Secure FTD Software. This <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-53825-unauthenticated-preview-deployment-vulnerability-in-dokploy\/\"  data-wpil-monitor-id=\"72002\">vulnerability exposes the system to an unauthenticated<\/a>, remote attacker who can trigger a Denial of Service (DoS) condition, leading to an unexpected system reload and potentially resulting in severe system compromise or data leakage. Any organization employing Cisco&#8217;s firewall and <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-20253-critical-vulnerability-in-ikev2-feature-of-cisco-software-could-lead-to-denial-of-service-dos-attack\/\"  data-wpil-monitor-id=\"76171\">FTD software<\/a> needs to be aware of this vulnerability, its potential impacts, and how to mitigate it.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-20243<br \/>\nSeverity: High (8.6 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27055-memory-corruption-leads-to-potential-system-compromise-during-image-encoding\/\"  data-wpil-monitor-id=\"74305\">Potential system compromise<\/a> or data leakage due to unexpected device reloads<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-2756406604\" 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><a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-20133-remote-access-ssl-vpn-vulnerability-in-cisco-secure-firewall-asa-software-and-secure-ftd-software\/\"  data-wpil-monitor-id=\"76821\">Cisco Secure Firewall ASA Software<\/a> | All versions up to latest patch<br \/>\n<a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-20136-denial-of-service-vulnerability-in-cisco-secure-firewall-asa-and-ftd-software\/\"  data-wpil-monitor-id=\"76915\">Cisco Secure FTD<\/a> Software | All versions up to latest patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47982-improper-input-validation-vulnerability-in-windows-storage-vsp-driver-leading-to-privilege-escalation\/\"  data-wpil-monitor-id=\"75592\">vulnerability lies in the improper validation of user-supplied input<\/a> on an interface with VPN web services. If an attacker can craft a malicious <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-23317-nvidia-triton-inference-server-http-server-vulnerability\/\"  data-wpil-monitor-id=\"82302\">HTTP request and send it to a targeted web server<\/a> on an affected device, they can exploit this vulnerability. This exploitation causes the device to reload unexpectedly, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-52496-race-condition-in-mbed-tls-library-leads-to-potential-aes-key-extraction\/\"  data-wpil-monitor-id=\"76152\">leading to a DoS condition<\/a>. The unexpected reload could <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27043-memory-corruption-vulnerability-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"75593\">potentially give the attacker an opportunity to compromise the system<\/a> or leak sensitive data.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-4270563090\" 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 sample HTTP <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-9408-server-side-request-forgery-attack-in-eclipse-glassfish\/\"  data-wpil-monitor-id=\"77406\">request showing how an attacker<\/a> might send a malicious payload.<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/cisco_vpn_endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ &quot;malicious_payload&quot;: &quot;Exploit_CVE-2025-20243&quot; }<\/code><\/pre>\n<p>Please note that this is a conceptual example and does not represent actual <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8714-critical-postgresql-vulnerability-allowing-malicious-code-injection-by-superusers\/\"  data-wpil-monitor-id=\"80764\">malicious code<\/a>. It&#8217;s crucial to understand this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27052-memory-corruption-vulnerability-in-unix-clients-processing-data-packets\/\"  data-wpil-monitor-id=\"74127\">process to ensure the vulnerability<\/a> is adequately addressed and mitigated.<\/p>\n<p><strong>Recommended Mitigations<\/strong><\/p>\n<p>The best line of <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-20217-denial-of-service-vulnerability-in-snort-3-detection-engine-of-cisco-secure-firewall-threat-defense-software\/\"  data-wpil-monitor-id=\"76929\">defense for this vulnerability<\/a> is to apply the vendor-supplied patch to all affected devices. If the patch cannot be applied immediately, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as temporary mitigations. These systems can help detect and block the malicious HTTP <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-52797-critical-cross-site-request-forgery-csrf-vulnerability-in-josepsitjar-storymap\/\"  data-wpil-monitor-id=\"79413\">requests that exploit this vulnerability<\/a>. Regularly updating all software and systems to their latest <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43588-out-of-bounds-write-vulnerability-in-substance3d-sampler-versions-5-0-and-earlier\/\"  data-wpil-monitor-id=\"73518\">versions can also help prevent such vulnerabilities<\/a> from being exploited.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview In the world of cybersecurity, any weak link in a system&#8217;s defense can lead to disastrous consequences. This is particularly the case with vulnerabilities like CVE-2025-20243, which predominantly affects Cisco&#8217;s Secure Firewall ASA Software and Secure FTD Software. This vulnerability exposes the system to an unauthenticated, remote attacker who can trigger a Denial of [&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":[1],"tags":[],"vendor":[96],"product":[],"attack_vector":[87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-64276","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-cisco","attack_vector-dos"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64276","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=64276"}],"version-history":[{"count":14,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64276\/revisions"}],"predecessor-version":[{"id":74815,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64276\/revisions\/74815"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=64276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=64276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=64276"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=64276"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=64276"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=64276"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=64276"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=64276"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=64276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}