{"id":85573,"date":"2025-11-03T23:54:57","date_gmt":"2025-11-03T23:54:57","guid":{"rendered":""},"modified":"2025-11-11T11:04:01","modified_gmt":"2025-11-11T17:04:01","slug":"cve-2025-54899-unauthorized-code-execution-through-memory-mismanagement-in-microsoft-office-excel","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-54899-unauthorized-code-execution-through-memory-mismanagement-in-microsoft-office-excel\/","title":{"rendered":"<strong>CVE-2025-54899: Unauthorized Code Execution through Memory Mismanagement in Microsoft Office Excel<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The vulnerability, identified as CVE-2025-54899, pertains to Microsoft Office Excel&#8217;s flaw in memory management, which allows for unauthorized local code execution. This critical vulnerability affects all users of the said software and poses a significant threat due to the potential for system compromise or data leakage if exploited.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-54899<br \/>\nSeverity: High (7.8 CVSS Score)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49668-heap-based-buffer-overflow-in-windows-rras-resulting-in-potential-system-compromise\/\"  data-wpil-monitor-id=\"92479\">Potential system<\/a> compromise and data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-415758286\" 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>Microsoft Office Excel | All versions prior to patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability stems from an error in Excel&#8217;s memory management, specifically in the freeing of memory not on the heap. An attacker can exploit this flaw by inducing a condition wherein Excel attempts to free memory that was not allocated on the heap. This could allow the attacker to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-2945-critical-remote-code-execution-vulnerability-in-pgadmin-4\/\"  data-wpil-monitor-id=\"92494\">execute arbitrary code<\/a> on the victim&#8217;s system, leading to a potential system compromise or data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-712595933\" 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>Given the nature of the vulnerability, an example exploit could involve a specially crafted Excel file that, when opened, triggers the memory mismanagement issue and executes arbitrary code. Conceptually, this could look like:<\/p>\n<pre><code class=\"\" data-line=\"\">Sub Workbook_Open()\n&#039; Malicious payload that triggers memory mismanagement\nDim buffer As String\nbuffer = String(1000000, &quot;A&quot;)\nEnd Sub<\/code><\/pre>\n<p>In this conceptual example, the malicious Excel file contains VBA code that is automatically executed when the file is opened. The code attempts to allocate an excessively large amount of memory, simulating a condition that could lead to the vulnerability being exploited. Note that this is a simplified example and actual exploitation would likely involve more complex techniques.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The vulnerability, identified as CVE-2025-54899, pertains to Microsoft Office Excel&#8217;s flaw in memory management, which allows for unauthorized local code execution. This critical vulnerability affects all users of the said software and poses a significant threat due to the potential for system compromise or data leakage if exploited. Vulnerability Summary CVE ID: CVE-2025-54899 Severity: [&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":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-85573","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-microsoft"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85573","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=85573"}],"version-history":[{"count":2,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85573\/revisions"}],"predecessor-version":[{"id":85779,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85573\/revisions\/85779"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=85573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=85573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=85573"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=85573"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=85573"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=85573"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=85573"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=85573"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=85573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}