{"id":87058,"date":"2026-06-06T18:23:02","date_gmt":"2026-06-06T18:23:02","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-41252-high-risk-username-enumeration-vulnerability-in-vmware-nsx","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-41252-high-risk-username-enumeration-vulnerability-in-vmware-nsx\/","title":{"rendered":"<strong>CVE-2025-41252: High-Risk Username Enumeration Vulnerability in VMware NSX<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The following report delves into a critical security vulnerability identified as CVE-2025-41252. This vulnerability resides in several versions of VMware NSX and VMware Cloud Foundation (with NSX), enabling unauthenticated malicious actors to enumerate valid usernames remotely, which can potentially lead to unauthorized access attempts. Given its severity and wide impact, understanding and addressing this vulnerability is crucial for organizations relying on affected VMware products.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-41252<br \/>\nSeverity: Important, CVSSv3: 7.5 (High)<br \/>\nAttack Vector: Remote, Unauthenticated<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: Username enumeration leading to potential system compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1782694598\" 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>VMware NSX | 9.x.x.x, 4.2.x, 4.1.x, 4.0.x<br \/>\nNSX-T | 3.x<br \/>\nVMware Cloud Foundation (with NSX) | 5.x, 4.5.x<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability resides in the user authentication component of the VMware NSX. An unauthenticated malicious actor can send specially crafted requests to the login interface of the affected products. These requests can disclose whether a user exists, allowing the attacker to create a list of valid usernames. With this information, the attacker can potentially carry out further attacks, such as brute-force or password spraying attacks, to gain unauthorized access.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-2712803102\" 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 conceptual example of how the vulnerability might be exploited using an HTTP request:<\/p>\n<pre><code class=\"\" data-line=\"\">GET \/login HTTP\/1.1\nHost: target.example.com\nUser-Agent: Mozilla\/5.0\n{ &quot;username&quot;: &quot;admin&quot; }<\/code><\/pre>\n<p>In this case, the server&#8217;s response might differ depending on whether the &#8220;admin&#8221; username exists, allowing an attacker to enumerate valid usernames.<\/p>\n<p><strong>Workarounds and Mitigation<\/strong><\/p>\n<p>Unfortunately, no workarounds are currently available for CVE-2025-41252. The only way to effectively mitigate the vulnerability is by applying the patches provided by VMware for the affected products. Temporary measures can include the use of Web Application Firewalls (WAF) or Intrusion Detection Systems (IDS). However, these are not full-proof solutions and the recommended approach is to apply the patches as soon as possible.<\/p>\n<p><strong>Acknowledgments<\/strong><\/p>\n<p>This vulnerability was reported by the National Security Agency.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The following report delves into a critical security vulnerability identified as CVE-2025-41252. This vulnerability resides in several versions of VMware NSX and VMware Cloud Foundation (with NSX), enabling unauthenticated malicious actors to enumerate valid usernames remotely, which can potentially lead to unauthorized access attempts. Given its severity and wide impact, understanding and addressing this [&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-87058","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/87058","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=87058"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/87058\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=87058"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=87058"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=87058"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=87058"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=87058"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=87058"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=87058"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=87058"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=87058"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}