{"id":34287,"date":"2025-05-03T02:49:37","date_gmt":"2025-05-03T02:49:37","guid":{"rendered":""},"modified":"2025-09-11T12:31:06","modified_gmt":"2025-09-11T18:31:06","slug":"cve-2025-3935-viewstate-code-injection-vulnerability-in-screenconnect","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-3935-viewstate-code-injection-vulnerability-in-screenconnect\/","title":{"rendered":"<strong>CVE-2025-3935: ViewState Code Injection Vulnerability in ScreenConnect<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The cybersecurity landscape is ever-evolving with new vulnerabilities surfacing frequently. One such vulnerability is the CVE-2025-3935, which affects ScreenConnect versions 25.2.3 and earlier. This vulnerability arises from an issue with ViewState, a feature used by ASP.NET <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-54693-critical-web-shell-upload-vulnerability-in-epiphyt-form-block\/\"  data-wpil-monitor-id=\"81714\">Web Forms<\/a> to preserve state information. If exploited, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32843-sql-injection-vulnerability-in-telecontrol-server-basic-leading-to-authorization-bypass-and-data-manipulation\/\"  data-wpil-monitor-id=\"39042\">vulnerability could lead to potential system compromise or data<\/a> leakage, underlining its significance in terms of cybersecurity.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-3935<br \/>\nSeverity: High (8.1 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: High (<a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43564-improper-access-control-vulnerability-in-coldfusion-leading-to-arbitrary-file-system-read\/\"  data-wpil-monitor-id=\"49402\">System level access<\/a>)<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32857-sql-injection-vulnerability-in-telecontrol-server-basic-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"39743\">Potential system<\/a> compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3107698159\" 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>ScreenConnect | 25.2.3 and earlier versions<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The exploit works by taking advantage of ViewState, a feature in ASP.NET Web Forms. ViewState preserves page and control states, encoding data using Base64 and protecting it with machine keys. If an <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-47663-unauthenticated-remote-attacker-gaining-full-access-due-to-improper-json-web-tokens-implementation\/\"  data-wpil-monitor-id=\"41625\">attacker gains access<\/a> to these machine keys, they could create a malicious ViewState and send it to the website. This <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32849-vulnerability-in-telecontrol-server-basic-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"39116\">potentially leads to remote code execution on the server<\/a>, hence compromising the system or leading to data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-565700415\" 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>A conceptual example of how this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-1305-cross-site-request-forgery-csrf-vulnerability-in-newsblogger-wordpress-theme\/\"  data-wpil-monitor-id=\"42551\">vulnerability might be exploited could be an HTTP request<\/a> like the one below, where the attacker injects a malicious ViewState:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/target\/endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x-www-form-urlencoded\n__VIEWSTATE=&lt;malicious ViewState here&gt;<\/code><\/pre>\n<p>Note that this is purely conceptual and would require the attacker to have already obtained the necessary machine keys to create a malicious ViewState.<\/p>\n<p><strong>Mitigation<\/strong><\/p>\n<p>The vendor has released a patch (ScreenConnect 2025.4) that disables ViewState, thus remedying the vulnerability. Users are urged to apply this patch as soon as possible. In the interim, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used for temporary mitigation. Security teams should also ensure that system level <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-1568-critical-access-control-vulnerability-in-google-chromeos\/\"  data-wpil-monitor-id=\"40082\">access is strictly controlled<\/a> and monitored to prevent unauthorized access.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The cybersecurity landscape is ever-evolving with new vulnerabilities surfacing frequently. One such vulnerability is the CVE-2025-3935, which affects ScreenConnect versions 25.2.3 and earlier. This vulnerability arises from an issue with ViewState, a feature used by ASP.NET Web Forms to preserve state information. If exploited, this vulnerability could lead to potential system compromise or data [&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":[],"product":[],"attack_vector":[78,80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-34287","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-injection","attack_vector-rce"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34287","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=34287"}],"version-history":[{"count":8,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34287\/revisions"}],"predecessor-version":[{"id":74168,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34287\/revisions\/74168"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=34287"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=34287"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=34287"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=34287"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=34287"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=34287"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=34287"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=34287"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=34287"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}