{"id":74640,"date":"2025-09-13T22:05:25","date_gmt":"2025-09-13T22:05:25","guid":{"rendered":""},"modified":"2025-10-01T17:01:56","modified_gmt":"2025-10-01T23:01:56","slug":"cve-2025-36854-critical-use-after-free-vulnerability-in-asp-net-leads-to-remote-code-execution","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-36854-critical-use-after-free-vulnerability-in-asp-net-leads-to-remote-code-execution\/","title":{"rendered":"<strong>CVE-2025-36854: Critical Use-After-Free Vulnerability in ASP.NET Leads to Remote Code Execution<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>Microsoft&#8217;s ASP.NET has been identified with a critical vulnerability, CVE-2025-36854, that could potentially lead to system compromise or data leakage. This vulnerability, discovered in end-of-life (EOL) versions of ASP.NET, is significant due to its potential to enable remote <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-50692-critical-code-execution-vulnerability-in-foxcms-v1-2-5\/\"  data-wpil-monitor-id=\"82158\">code execution<\/a>. It notably affects versions ASP.NET 6.0.0 to 6.0.36 and self-contained applications targeting these versions. Given the widespread usage of ASP.NET in web development, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-30403-heap-buffer-overflow-vulnerability-in-mvfst-impacts-quic-sessions\/\"  data-wpil-monitor-id=\"82310\">vulnerability could potentially impact<\/a> a significant number of applications and systems.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-36854<br \/>\nSeverity: Critical, CVSS score of 8.1<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: Remote <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-54886-arbitrary-code-execution-vulnerability-in-skops-python-library\/\"  data-wpil-monitor-id=\"82238\">Code Execution<\/a>, potential system compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3131692417\" 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>ASP.NET | 6.0.0 to 6.0.36<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability is rooted in a use-after-free error condition that occurs when closing an HTTP\/3 stream while application <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49530-out-of-bounds-write-vulnerability-in-adobe-illustrator\/\"  data-wpil-monitor-id=\"86208\">code<\/a> is writing to the response body. This situation creates a race condition that can lead to use-after-free, which subsequently results in remote <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-41413-arbitrary-code-execution-vulnerability-in-fuji-electric-smart-editor\/\"  data-wpil-monitor-id=\"82279\">code execution<\/a>. Essentially, the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-7775-critical-memory-overflow-vulnerability-in-netscaler-adc-and-gateway-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"83719\">vulnerability arises from the improper handling of memory<\/a> operations, specifically, it reuses or references memory after it has been freed. Any operations performed using the original pointer become invalid, leading to the potential <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27128-arbitrary-code-execution-vulnerability-in-openharmony-v5-0-3\/\"  data-wpil-monitor-id=\"82199\">execution of arbitrary code<\/a>.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1151766087\" 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 hypothetical example of how this vulnerability could be exploited. The example assumes an HTTP\/3 stream is being closed while application <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47129-out-of-bounds-write-vulnerability-in-adobe-framemaker-with-potential-for-arbitrary-code-execution\/\"  data-wpil-monitor-id=\"86882\">code is writing<\/a> to the response body:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/vulnerable\/endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ &quot;command&quot;: &quot;close_http3_stream&quot;, &quot;data&quot;: &quot;writing to response body&quot; }<\/code><\/pre>\n<p>In this example, the malicious actor sends a POST request to close the HTTP\/3 stream while data is being written to the response body, triggering the use-after-free condition and potentially leading to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-55733-critical-remote-code-execution-vulnerability-in-deepchat-ai-assistant\/\"  data-wpil-monitor-id=\"82282\">remote code execution<\/a>.<\/p>\n<p><strong>Recommended Mitigation<\/strong><\/p>\n<p>Due to the end-of-life status of the affected software components, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-30379-release-of-invalid-pointer-in-microsoft-office-excel-leading-to-local-code-execution\/\"  data-wpil-monitor-id=\"91938\">Microsoft will not be releasing<\/a> any further updates or support. As such, users are advised to apply a vendor patch or use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. Furthermore, if you&#8217;ve deployed self-contained applications targeting any of the impacted versions, these applications must be recompiled and redeployed to ensure security.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview Microsoft&#8217;s ASP.NET has been identified with a critical vulnerability, CVE-2025-36854, that could potentially lead to system compromise or data leakage. This vulnerability, discovered in end-of-life (EOL) versions of ASP.NET, is significant due to its potential to enable remote code execution. It notably affects versions ASP.NET 6.0.0 to 6.0.36 and self-contained applications targeting these versions. [&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":[82],"product":[],"attack_vector":[80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-74640","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-microsoft","attack_vector-rce"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74640","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=74640"}],"version-history":[{"count":10,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74640\/revisions"}],"predecessor-version":[{"id":85122,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74640\/revisions\/85122"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=74640"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=74640"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=74640"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=74640"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=74640"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=74640"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=74640"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=74640"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=74640"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}