{"id":74646,"date":"2025-09-14T00:06:02","date_gmt":"2025-09-14T00:06:02","guid":{"rendered":""},"modified":"2025-10-01T13:45:29","modified_gmt":"2025-10-01T19:45:29","slug":"cve-2021-26383-critical-vulnerability-in-amd-tee-puts-system-integrity-and-data-availability-in-jeopardy","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2021-26383-critical-vulnerability-in-amd-tee-puts-system-integrity-and-data-availability-in-jeopardy\/","title":{"rendered":"<strong>CVE-2021-26383: Critical Vulnerability in AMD TEE Puts System Integrity and Data Availability in Jeopardy<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>CVE-2021-26383 is a high-risk vulnerability found in the Trusted Execution Environment (TEE) of Advanced Micro Devices (AMD). This security flaw could potentially allow an attacker with a compromised userspace to invoke a command with malformed arguments. This could result in out-of-bounds memory access, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2022-45134-critical-vulnerability-in-mahara-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"82848\">leading to possible loss of system<\/a> integrity or data availability. It is essential to understand and mitigate this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-45968-insecure-direct-object-reference-vulnerability-in-system-pdv-v1-0\/\"  data-wpil-monitor-id=\"82995\">vulnerability as it can cause serious disruptions to system<\/a> operations and compromise sensitive data.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2021-26383<br \/>\nSeverity: High (7.9 CVSS Severity Score)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-9253-stack-based-buffer-overflow-on-linksys-wi-fi-range-extenders-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"84206\">Potential system<\/a> compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3647989307\" 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>AMD TEE | All <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-46715-kernel-pointer-vulnerability-in-sandboxie-versions-prior-to-1-15-12\/\"  data-wpil-monitor-id=\"82764\">versions prior<\/a> to vendor patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>In the case of CVE-2021-26383, an attacker who has gained access to a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8142-local-file-inclusion-vulnerability-in-soledad-wordpress-theme\/\"  data-wpil-monitor-id=\"82228\">local userspace can exploit the vulnerability<\/a> by invoking a command with malformed arguments. The insufficient bounds checking in the AMD TEE <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-57819-critical-vulnerability-in-freepbx-allowing-unauthenticated-access-and-remote-code-execution\/\"  data-wpil-monitor-id=\"86552\">allows these malformed arguments to access<\/a> memory out of the allocated bounds. This results in an illegal <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=\"83706\">memory access which can lead to unpredictable system<\/a> behavior, potentially allowing the attacker to compromise the system or leak data.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1406645255\" 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>The following is a conceptual example of how the vulnerability might be exploited. Note, this is a simplified representation and actual exploit code may be more complex:<\/p>\n<pre><code class=\"\" data-line=\"\"># Attacker has access to the local userspace\n$ .\/exploit-program --malformed-argument<\/code><\/pre>\n<p>In this example, it&#8217;s assumed that the attacker has already compromised the userspace and is able to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27128-arbitrary-code-execution-vulnerability-in-openharmony-v5-0-3\/\"  data-wpil-monitor-id=\"82213\">execute arbitrary<\/a> commands. The `exploit-program` represents any program running in the AMD TEE, and `&#8211;malformed-argument` is an argument that can cause <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43300-out-of-bounds-write-issue-in-macos-and-ios-resulting-in-memory-corruption\/\"  data-wpil-monitor-id=\"84415\">out-of-bounds memory<\/a> access due to insufficient bounds checking.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>The primary mitigation for this vulnerability is to apply the vendor patch provided by AMD. This patch corrects the bounds checking issue, preventing the potential for <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-57052-cjson-out-of-bounds-access-vulnerability-and-mitigation\/\"  data-wpil-monitor-id=\"86828\">out-of-bounds memory access<\/a>.<br \/>\nIf immediate patching is not possible, a temporary mitigation can be implementing a Web Application Firewall (WAF) or an Intrusion Detection System (IDS). These security measures can help detect and <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8418-arbitrary-plugin-installation-vulnerability-in-b-slider-gutenberg-slider-block-for-wp-plugin\/\"  data-wpil-monitor-id=\"82547\">block attempts to exploit this vulnerability<\/a>. However, they should be considered a temporary solution until the vendor patch can be applied.<br \/>\nPlease note, the effectiveness of WAFs and IDSs as a mitigation for this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-1740-excessive-authentication-attempts-vulnerability-in-akinsoft-myrezzta\/\"  data-wpil-monitor-id=\"86760\">vulnerability depends on accurately identifying and blocking exploit attempts<\/a>, which might not always be possible. Therefore, applying the vendor patch remains the most reliable solution.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview CVE-2021-26383 is a high-risk vulnerability found in the Trusted Execution Environment (TEE) of Advanced Micro Devices (AMD). This security flaw could potentially allow an attacker with a compromised userspace to invoke a command with malformed arguments. This could result in out-of-bounds memory access, leading to possible loss of system integrity or data availability. It [&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":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-74646","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74646","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=74646"}],"version-history":[{"count":12,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74646\/revisions"}],"predecessor-version":[{"id":79668,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/74646\/revisions\/79668"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=74646"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=74646"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=74646"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=74646"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=74646"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=74646"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=74646"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=74646"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=74646"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}