{"id":86766,"date":"2026-03-24T15:42:35","date_gmt":"2026-03-24T15:42:35","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-4276-arbitrary-memory-write-and-code-execution-vulnerability-in-usbcoredxe","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-4276-arbitrary-memory-write-and-code-execution-vulnerability-in-usbcoredxe\/","title":{"rendered":"<strong>CVE-2025-4276: Arbitrary Memory Write and Code Execution Vulnerability in UsbCoreDxe<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The CVE-2025-4276 is a critical vulnerability found in UsbCoreDxe that allows an attacker to write arbitrary memory inside System Management Mode RAM (SMRAM) and execute arbitrary code at the System Management Mode (SMM) level. This vulnerability, if exploited, can cause severe damage including potential system compromise or data leakage, thus posing a significant threat to any system that uses UsbCoreDxe.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-4276<br \/>\nSeverity: High (7.5 CVSS)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: System Level<br \/>\nUser Interaction: None<br \/>\nImpact: Successful exploitation can lead to system compromise and potential data leakage.<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1727264661\" 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>UsbCoreDxe | All versions prior to patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>An attacker, having gained system-level privileges, can exploit this vulnerability by writing arbitrary memory inside SMRAM, a protected region of memory used by the operating system. Once the memory is written, the attacker can then execute arbitrary code at the SMM level. The SMM is a special operating mode in which the system firmware operates, providing an isolated environment that is secure even from the operating system. By gaining control at this level, an attacker can manipulate the system at a very fundamental level, potentially bypassing all security measures.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1451733394\" 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>This is a conceptual example of how an attacker might exploit this vulnerability. Note that specific details may vary depending on the exact system configuration and the attacker&#8217;s objectives.<\/p>\n<pre><code class=\"\" data-line=\"\">#include &lt;smm.h&gt;\nvoid exploit() {\n\/\/ Gain system-level privileges\nelevate_privileges();\n\/\/ Write arbitrary memory inside SMRAM\nsmm_write(0x1000, &quot;arbitrary code&quot;, 14);\n\/\/ Execute arbitrary code at SMM level\nsmm_execute(0x1000);\n}<\/code><\/pre>\n<p>Please note that this is a simplified and conceptual example. Actual exploit code would be much more complex and specific to the exact system configuration and the attacker&#8217;s objectives.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The CVE-2025-4276 is a critical vulnerability found in UsbCoreDxe that allows an attacker to write arbitrary memory inside System Management Mode RAM (SMRAM) and execute arbitrary code at the System Management Mode (SMM) level. This vulnerability, if exploited, can cause severe damage including potential system compromise or data leakage, thus posing a significant threat [&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-86766","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86766","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=86766"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86766\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86766"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86766"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86766"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86766"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86766"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86766"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86766"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86766"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86766"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}