{"id":34035,"date":"2025-05-01T08:17:20","date_gmt":"2025-05-01T08:17:20","guid":{"rendered":""},"modified":"2025-05-19T06:52:08","modified_gmt":"2025-05-19T06:52:08","slug":"cve-2025-43715-privilege-escalation-vulnerability-in-nullsoft-scriptable-install-system-nsis","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-43715-privilege-escalation-vulnerability-in-nullsoft-scriptable-install-system-nsis\/","title":{"rendered":"<strong>CVE-2025-43715: Privilege Escalation Vulnerability in Nullsoft Scriptable Install System (NSIS)<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>CVE-2025-43715 is a significant security vulnerability that affects the Nullsoft Scriptable Install System (NSIS) on Windows platforms. This vulnerability allows local users to escalate their privileges to SYSTEM during an installation process. It pertains to how NSIS handles temporary plugins directory creation during installations, making it susceptible to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2023-33110-race-condition-vulnerability-in-pcm-host-voice-audio-driver\/\"  data-wpil-monitor-id=\"41227\">race condition<\/a> exploits. The vulnerability is of particular concern because it could potentially enable <a href=\"https:\/\/www.ameeba.com\/blog\/yale-new-haven-health-system-data-breach-a-comprehensive-analysis-of-a-cybersecurity-breach-impacting-5-5-million-patients\/\"  data-wpil-monitor-id=\"38613\">system compromise or data<\/a> leakage, posing a serious risk to users and their sensitive information.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-43715<br \/>\nSeverity: High (8.1 CVSS v3.0 Score)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-3914-potential-arbitrary-file-uploads-and-system-compromise-in-aeropage-sync-for-airtable-wordpress-plugin\/\"  data-wpil-monitor-id=\"40584\">System compromise<\/a> or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1480804812\" 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>Nullsoft Scriptable Install System | Before 3.11<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The exploit of CVE-2025-43715 revolves around the temporary <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-1562-unauthorized-arbitrary-plugin-installation-in-funnelkit-plugin-for-wordpress\/\"  data-wpil-monitor-id=\"62461\">plugins directory that NSIS creates under %WINDIR%temp during an installation<\/a> process. By winning a race condition, unprivileged users can place a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32432-remote-code-execution-vulnerability-in-craft-cms\/\"  data-wpil-monitor-id=\"40509\">crafted executable<\/a> file in this directory. Since NSIS&#8217;s EW_CREATEDIR does not always set the CreateRestrictedDirectory error flag, this allows the system to execute the crafted file with elevated SYSTEM privileges, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32849-vulnerability-in-telecontrol-server-basic-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"39102\">leading to a potential system<\/a> compromise or data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-146249330\" 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>Even though the actual exploit process involves wining a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-1290-high-severity-race-condition-use-after-free-vulnerability-in-kernel-5-4-on-chromeos\/\"  data-wpil-monitor-id=\"41784\">race condition<\/a> and is complex to show in a simple code example, the conceptual pseudo-code below provides a simplified idea of how this vulnerability might be exploited:<\/p>\n<pre><code class=\"\" data-line=\"\"># pseudo-code\nimport os\nimport shutil\n# Locate the temporary plugins directory\ntemp_dir = os.environ[&#039;WINDIR&#039;] + &#039;\/temp&#039;\n# Crafted executable content\ncrafted_exe = &#039;...&#039;\n# Wait for the right moment (race condition)\nwhile not os.path.exists(temp_dir):\npass\n# Write the crafted executable to the temporary plugins directory\nwith open(os.path.join(temp_dir, &#039;crafted.exe&#039;), &#039;w&#039;) as f:\nf.write(crafted_exe)\n# The crafted executable will be executed with SYSTEM privileges during NSIS installation<\/code><\/pre>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>Users are recommended to apply the vendor-provided patch as soon as possible. If applying the patch immediately is not an option, using Web Application Firewalls (WAF) or Intrusion Detection Systems (IDS) can serve as a temporary mitigation measure. However, these do not completely remediate the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-3844-critical-authentication-bypass-vulnerability-in-peprodev-ultimate-profile-solutions-plugin-for-wordpress\/\"  data-wpil-monitor-id=\"45136\">vulnerability and are merely stopgap solutions<\/a>. The only comprehensive solution is to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-2817-system-level-updater-vulnerability-in-thunderbird-s-update-mechanism\/\"  data-wpil-monitor-id=\"41084\">update NSIS to a version that has addressed this vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview CVE-2025-43715 is a significant security vulnerability that affects the Nullsoft Scriptable Install System (NSIS) on Windows platforms. This vulnerability allows local users to escalate their privileges to SYSTEM during an installation process. It pertains to how NSIS handles temporary plugins directory creation during installations, making it susceptible to race condition exploits. The vulnerability is [&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":[76],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-34035","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-microsoft","attack_vector-privilege-escalation"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34035","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=34035"}],"version-history":[{"count":9,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34035\/revisions"}],"predecessor-version":[{"id":56158,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34035\/revisions\/56158"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=34035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=34035"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=34035"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=34035"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=34035"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=34035"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=34035"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=34035"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=34035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}