{"id":56613,"date":"2025-07-02T09:00:58","date_gmt":"2025-07-02T09:00:58","guid":{"rendered":""},"modified":"2025-10-29T17:39:04","modified_gmt":"2025-10-29T23:39:04","slug":"cve-2025-29977-use-after-free-vulnerability-in-microsoft-office-excel","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-29977-use-after-free-vulnerability-in-microsoft-office-excel\/","title":{"rendered":"<strong>CVE-2025-29977: Use After Free Vulnerability in Microsoft Office Excel<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>A critical vulnerability has been identified in Microsoft Office Excel, a widely used spreadsheet application, which could potentially allow an unauthorized attacker to execute arbitrary code on a victim\u2019s system. This flaw, assigned the identification number CVE-2025-29977, is a &#8216;use-after-free&#8217; vulnerability, a type of security bug that can lead to malicious code execution or even total system compromise.<br \/>\nThe vulnerability is of significant concern due to the widespread usage of <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-29976-improper-privilege-management-vulnerability-in-microsoft-office-sharepoint\/\"  data-wpil-monitor-id=\"64901\">Microsoft<\/a> Office Excel across various fields including business, academia, and personal computing. The potential for <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32875-unencrypted-bluetooth-data-transmission-vulnerability-in-coros-application\/\"  data-wpil-monitor-id=\"63050\">data leakage or system compromise makes this vulnerability<\/a> a pressing issue that requires immediate attention.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-29977<br \/>\nSeverity: High (7.8\/10)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-6370-critical-vulnerability-in-d-link-dir-619l-2-06b01-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"63422\">Potential system<\/a> compromise and data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-4030005666\" 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><a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-29978-use-after-free-vulnerability-in-microsoft-office-powerpoint-allowing-unauthorized-local-code-execution\/\"  data-wpil-monitor-id=\"64868\">Microsoft Office<\/a> Excel | All versions prior to the patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-6424-critical-use-after-free-vulnerability-in-firefox\/\"  data-wpil-monitor-id=\"64306\">vulnerability arises from a use-after-free<\/a> condition in Microsoft Office Excel. In a use-after-free scenario, a section of the memory is used after it has been freed, leading to unexpected behavior such as crashing the program or, in this case, allowing for <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49132-critical-arbitrary-code-execution-vulnerability-in-pterodactyl-game-server-management-panel\/\"  data-wpil-monitor-id=\"63281\">arbitrary code execution<\/a>.<br \/>\nThe flaw can be exploited when an attacker tricks a user into opening a specially crafted Excel <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-4981-critical-file-extraction-vulnerability-in-mattermost-leading-to-potential-remote-code-execution\/\"  data-wpil-monitor-id=\"63090\">file containing malicious code<\/a>. Once the file is opened, the code is executed locally, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32878-critical-vulnerability-in-coros-pace-3-devices-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"63282\">potentially leading to system<\/a> compromise or data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3213376486\" 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>Here is a<br \/>\n<strong>conceptual<\/strong><br \/>\n example of how the vulnerability might be exploited:<\/p>\n<pre><code class=\"\" data-line=\"\"># Command to open a malicious Excel file\nopen &quot;\/path\/to\/malicious\/file.xls&quot;<\/code><\/pre>\n<p>In this conceptual example, an attacker would craft a malicious Excel <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-9693-arbitrary-file-deletion-vulnerability-in-user-meta-user-profile-builder-plugin-for-wordpress\/\"  data-wpil-monitor-id=\"90628\">file and trick the user<\/a> into opening it. Once opened, the malicious <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-52921-critical-vulnerability-in-innoshop-allows-code-execution-by-authenticated-attackers\/\"  data-wpil-monitor-id=\"63505\">code contained within the file would execute<\/a>, exploiting the use-after-free vulnerability.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>To mitigate the effects of this vulnerability, users are strongly advised to apply the patch provided by <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-30383-type-confusion-vulnerability-in-microsoft-office-excel-leading-to-unauthorized-code-execution\/\"  data-wpil-monitor-id=\"91850\">Microsoft<\/a> as soon as it is available. As a temporary measure, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can help detect and prevent exploitation attempts. Regularly updating and patching software can also go a long way in preventing such <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-53277-critical-cross-site-request-forgery-csrf-vulnerability-in-infigo-software-is-theme-companion\/\"  data-wpil-monitor-id=\"65659\">vulnerabilities<\/a> from being exploited.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview A critical vulnerability has been identified in Microsoft Office Excel, a widely used spreadsheet application, which could potentially allow an unauthorized attacker to execute arbitrary code on a victim\u2019s system. This flaw, assigned the identification number CVE-2025-29977, is a &#8216;use-after-free&#8217; vulnerability, a type of security bug that can lead to malicious code execution or [&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-56613","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\/56613","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=56613"}],"version-history":[{"count":11,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/56613\/revisions"}],"predecessor-version":[{"id":85028,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/56613\/revisions\/85028"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=56613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=56613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=56613"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=56613"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=56613"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=56613"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=56613"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=56613"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=56613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}