{"id":59634,"date":"2025-07-25T13:13:01","date_gmt":"2025-07-25T13:13:01","guid":{"rendered":""},"modified":"2025-09-08T17:18:42","modified_gmt":"2025-09-08T23:18:42","slug":"cve-2025-53770-critical-deserialization-vulnerability-in-microsoft-sharepoint-server","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-53770-critical-deserialization-vulnerability-in-microsoft-sharepoint-server\/","title":{"rendered":"<strong>CVE-2025-53770: Critical Deserialization Vulnerability in Microsoft SharePoint Server<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The CVE-2025-53770 is a severe vulnerability discovered in Microsoft SharePoint Server that allows unauthorized attackers to execute harmful code over a network by deserializing untrusted data. This vulnerability primarily affects organizations using on-premises Microsoft SharePoint Server, posing a substantial threat to their system security. Remediation of this vulnerability is of paramount importance as an exploit for this flaw already exists in the wild, increasing the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-25178-critical-luajit-vulnerability-puts-systems-at-risk-of-compromise\/\"  data-wpil-monitor-id=\"70588\">risk of system<\/a> compromise and data leakage.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-53770<br \/>\nSeverity: Critical (9.8 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-31278-memory-corruption-vulnerability-with-potential-system-compromise\/\"  data-wpil-monitor-id=\"70558\">Potential system<\/a> compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-633193223\" 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-2025-53786-microsoft-exchange-server-security-vulnerability-in-hybrid-deployments\/\"  data-wpil-monitor-id=\"81277\">Microsoft SharePoint Server<\/a> | All on-premises versions<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-50105-critical-vulnerability-in-oracle-universal-work-queue-allowing-unauthorized-data-access\/\"  data-wpil-monitor-id=\"68675\">vulnerability stems from the deserialization of untrusted data<\/a> in Microsoft SharePoint Server. Deserialization is a process that converts a byte stream into an object. In this case, an attacker sends a serialized object containing <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8714-critical-postgresql-vulnerability-allowing-malicious-code-injection-by-superusers\/\"  data-wpil-monitor-id=\"80669\">malicious code<\/a> to the server. The server, not properly validating or checking the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-28961-critical-deserialization-of-untrusted-data-vulnerability-in-md-yeasin-ul-haider-url-shortener\/\"  data-wpil-monitor-id=\"70557\">data it&#8217;s deserializing<\/a>, executes the harmful code, thereby granting the attacker the ability to perform actions on the system such as installing programs, deleting data, or creating new accounts with full user rights.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3893365080\" 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. This is a simplified example and actual exploit code may be more complex.<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/SharePoint\/endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/octet-stream\n{ &quot;serialized_object&quot;: &quot;rO0ABXNyABdqYXZhLnV0aWwuSGFzaE1hcAUH2sHDFmDRAwACRgAKbG9hZEZhY3RvckkACXRocmVzaG9sZHhwP0AAAAAAAAB3CAAAACAAAAAQAAAATlQAFm1hbGljaW91c19jb2RlX3RvX2JlX2V4ZWN1dGVk&quot; }<\/code><\/pre>\n<p>In this example, the attacker sends a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-8243-critical-buffer-overflow-vulnerability-in-totolink-x15-http-post-request-handler\/\"  data-wpil-monitor-id=\"68676\">POST request<\/a> to a SharePoint endpoint with a serialized object in the body of the request. This serialized object (encoded in Base64 for simplicity) contains malicious <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-50460-remote-code-execution-vulnerability-in-ms-swift-project\/\"  data-wpil-monitor-id=\"71474\">code that would be executed<\/a> upon deserialization on the server side.<br \/>\nRemember, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-7096-critical-vulnerability-in-comodo-internet-security-premium-12-3-4-8162\/\"  data-wpil-monitor-id=\"66714\">vulnerability can result in serious implications for system security<\/a>, and it&#8217;s critical to apply the vendor patch or use WAF\/IDS as a temporary mitigation until Microsoft releases a comprehensive update.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The CVE-2025-53770 is a severe vulnerability discovered in Microsoft SharePoint Server that allows unauthorized attackers to execute harmful code over a network by deserializing untrusted data. This vulnerability primarily affects organizations using on-premises Microsoft SharePoint Server, posing a substantial threat to their system security. Remediation of this vulnerability is of paramount importance as an [&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-59634","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\/59634","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=59634"}],"version-history":[{"count":7,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/59634\/revisions"}],"predecessor-version":[{"id":73726,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/59634\/revisions\/73726"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=59634"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=59634"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=59634"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=59634"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=59634"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=59634"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=59634"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=59634"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=59634"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}