{"id":86477,"date":"2026-02-16T07:25:14","date_gmt":"2026-02-16T07:25:14","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-33056-unauthorized-denial-of-service-vulnerability-in-microsoft-local-security-authority-server","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-33056-unauthorized-denial-of-service-vulnerability-in-microsoft-local-security-authority-server\/","title":{"rendered":"<strong>CVE-2025-33056: Unauthorized Denial of Service Vulnerability in Microsoft Local Security Authority Server<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The CVE-2025-33056 vulnerability relates to an improper access control issue within Microsoft Local Security Authority Server (lsasrv). This vulnerability allows an unauthorized attacker to inflict a Denial of Service (DoS) attack over a network, thereby potentially compromising the system or causing data leakage. This vulnerability represents a significant threat to any organizations or individuals utilizing affected versions of lsasrv.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-33056<br \/>\nSeverity: High (7.5 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: Unauthorized DoS, potential system compromise, and data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1400159945\" 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 Local Security Authority Server | All versions prior to the release of the patch<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability arises due to inadequate access controls within the Microsoft Local Security Authority Server. An attacker can exploit this by sending specially crafted network requests to the server, causing it to go into an unstable state and deny service to legitimate users. In some instances, this vulnerability could also lead to unauthorized access, system compromise, or data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3002737970\" 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>Below is a conceptual example of how the vulnerability might be exploited. Note that this is a simplified example and actual exploitation would likely involve more complex network interactions.<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/lsasrv\/control HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ &quot;exploit&quot;: &quot;specially_crafted_request_to_trigger_dos&quot; }<\/code><\/pre>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>To mitigate this vulnerability, apply the vendor-released patch immediately. If applying the patch is not immediately feasible, implementing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These systems should be configured to detect and block the specific network interactions that can lead to exploitation of this vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The CVE-2025-33056 vulnerability relates to an improper access control issue within Microsoft Local Security Authority Server (lsasrv). This vulnerability allows an unauthorized attacker to inflict a Denial of Service (DoS) attack over a network, thereby potentially compromising the system or causing data leakage. This vulnerability represents a significant threat to any organizations or individuals [&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-86477","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86477","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=86477"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86477\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86477"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86477"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86477"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86477"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86477"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86477"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86477"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86477"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86477"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}