{"id":64278,"date":"2025-08-24T03:12:12","date_gmt":"2025-08-24T03:12:12","guid":{"rendered":""},"modified":"2025-10-02T23:37:09","modified_gmt":"2025-10-03T05:37:09","slug":"cve-2025-20263-critical-buffer-overflow-vulnerability-in-cisco-secure-firewall","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20263-critical-buffer-overflow-vulnerability-in-cisco-secure-firewall\/","title":{"rendered":"<strong>CVE-2025-20263: Critical Buffer Overflow Vulnerability in Cisco Secure Firewall<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The cybersecurity community has recently identified a critical vulnerability, CVE-2025-20263, that affects Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability has the potential to compromise the stability and security of systems running these applications, making it a significant threat to organizations that rely on Cisco&#8217;s secure firewall services. Its severity is underscored by its high CVSS score and the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27055-memory-corruption-leads-to-potential-system-compromise-during-image-encoding\/\"  data-wpil-monitor-id=\"74306\">potential for system compromise<\/a> or data leakage.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-20263<br \/>\nSeverity: Critical (8.6 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: A successful exploit could cause a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8184-critical-stack-based-buffer-overflow-vulnerability-in-d-link-dir-513\/\"  data-wpil-monitor-id=\"71762\">buffer overflow<\/a> condition that leads to a system reload, resulting in a denial of service (DoS) condition. This could <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-30327-integer-overflow-vulnerability-in-incopy-leading-to-potential-arbitrary-code-execution\/\"  data-wpil-monitor-id=\"73603\">potentially lead<\/a> to system compromise or data leakage.<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1350539695\" 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: 720px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 22px; font-weight: 600; display: flex; align-items: center; letter-spacing: -0.02em;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 10px;\">\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: 42px; height: 42px;\" \/>\r\n    <\/a>\r\n    Share secrets securely\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 14px; color: #d1d5db;\">\r\n    Ameeba is private infrastructure for communication and sensitive work built on encrypted identity instead of exposed corporate identity systems.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 18px; color: #a1a1aa;\">\r\n    Passwords, credentials, confidential files, screenshots, internal discussions, sensitive AI context, and private coordination should not become exposed across ordinary communication platforms.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 24px; color: #e4e4e7;\">\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Encrypted identity<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Private Spaces for organizations and teams<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 End-to-end encrypted chat, calls, files, and notes<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Sensitive AI work and protected collaboration<\/li>\r\n    <li>\u2022 Built for information that cannot leak<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px; color: #ffffff;\">\r\n    Our mission is to secure human work alongside AI.\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: 8px; font-weight: 500;\">\r\n      Download Ameeba\r\n    <\/a>\r\n\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 8px; font-weight: 500;\">\r\n      Learn More\r\n    <\/a>\r\n  <\/div>\r\n<\/div><\/div>\n<p>Product | Affected Versions<\/p>\n<p><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=\"76174\">Cisco Secure Firewall ASA Software<\/a> | All current versions until patched<br \/>\n<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=\"76826\">Cisco Secure Firewall FTD Software<\/a> | All current versions until patched<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-24777-deserialization-of-untrusted-data-vulnerability-in-awethemes-hillter\/\"  data-wpil-monitor-id=\"73006\">vulnerability is due to insufficient boundary checks for specific data<\/a> provided to the web services interface of an affected system. An attacker could exploit this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-9408-server-side-request-forgery-attack-in-eclipse-glassfish\/\"  data-wpil-monitor-id=\"77407\">vulnerability<\/a> by sending a maliciously crafted HTTP request to the affected system. The improper boundary checks facilitate a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-7463-critical-buffer-overflow-vulnerability-in-tenda-fh1201-1-2-0-14\/\"  data-wpil-monitor-id=\"71810\">buffer overflow<\/a> condition, causing the system to reload and leading to a DoS condition.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3564163109\" 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 an attacker might exploit this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-52797-critical-cross-site-request-forgery-csrf-vulnerability-in-josepsitjar-storymap\/\"  data-wpil-monitor-id=\"79350\">vulnerability using a malicious HTTP request:<\/a><\/p>\n<pre><code class=\"\" data-line=\"\">POST \/asa_endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/xml\n{ &quot;payload&quot;: &quot;&lt;!-[malicious XML data exceeding buffer capacity]-&gt;&quot; }<\/code><\/pre>\n<p>In this example, the attacker sends a POST request with a payload containing XML data that exceeds the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8939-buffer-overflow-vulnerability-in-tenda-ac20-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"78266\">buffer capacity of the system&#8217;s<\/a> web services interface. This triggers a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49691-heap-based-buffer-overflow-in-windows-media-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"72058\">buffer overflow<\/a> condition, which in turn causes the system to reload and results in a denial of service.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>Users are advised to apply vendor patches as soon as they become <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-26383-critical-vulnerability-in-amd-tee-puts-system-integrity-and-data-availability-in-jeopardy\/\"  data-wpil-monitor-id=\"88032\">available to remediate this vulnerability<\/a>. In the absence of a patch, users can utilize Web Application Firewall (WAF) or Intrusion Detection Systems (IDS) as temporary mitigation measures. These tools can help to monitor network traffic for malicious activity and prevent any <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-40741-stack-based-overflow-vulnerability-in-solid-edge-se2025-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"75747\">potential exploitation of this vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The cybersecurity community has recently identified a critical vulnerability, CVE-2025-20263, that affects Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. This vulnerability has the potential to compromise the stability and security of systems running these applications, making it a significant threat to organizations that rely on [&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":[86,87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-64278","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-cisco","attack_vector-buffer-overflow","attack_vector-dos"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64278","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=64278"}],"version-history":[{"count":13,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64278\/revisions"}],"predecessor-version":[{"id":80848,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/64278\/revisions\/80848"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=64278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=64278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=64278"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=64278"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=64278"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=64278"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=64278"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=64278"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=64278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}