{"id":55137,"date":"2025-06-25T22:55:25","date_gmt":"2025-06-25T22:55:25","guid":{"rendered":""},"modified":"2025-10-02T23:37:11","modified_gmt":"2025-10-03T05:37:11","slug":"cve-2025-4981-critical-file-extraction-vulnerability-in-mattermost-leading-to-potential-remote-code-execution","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-4981-critical-file-extraction-vulnerability-in-mattermost-leading-to-potential-remote-code-execution\/","title":{"rendered":"<strong>CVE-2025-4981: Critical File Extraction Vulnerability in Mattermost Leading to Potential Remote Code Execution<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The vulnerability in focus, CVE-2025-4981, presents a significant security threat to a host of Mattermost versions. As a widely used open-source, self-hosted online chat service, Mattermost has a broad range of commercial and non-commercial users globally. The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49137-critical-vulnerability-in-hax-cms-php-prior-to-version-11-0-0\/\"  data-wpil-monitor-id=\"61945\">vulnerability arises from the failure of these versions<\/a> to sanitize filenames in the archive extractor, thereby providing authenticated users the potential to write files anywhere on the filesystem. This <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-6114-critical-vulnerability-in-d-link-dir-619l-leading-to-stack-based-buffer-overflow\/\"  data-wpil-monitor-id=\"61652\">vulnerability can lead<\/a> to remote code execution and consequently, a considerable system compromise or data leakage.<br \/>\nGiven the severity of the potential impact, understanding this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-39247-unauthenticated-admin-access-control-vulnerability-in-hikcentral-professional-versions\/\"  data-wpil-monitor-id=\"86129\">vulnerability is of paramount importance to cybersecurity professionals<\/a>, system administrators, and anyone who relies on Mattermost for their communication needs. It calls for immediate attention and mitigation to safeguard the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-26383-critical-vulnerability-in-amd-tee-puts-system-integrity-and-data-availability-in-jeopardy\/\"  data-wpil-monitor-id=\"88038\">integrity of these systems<\/a>.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-4981<br \/>\nSeverity: Critical (CVSS score 9.9)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: User<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-5866-critical-vulnerability-in-rt-thread-5-1-0-potentially-leading-to-system-compromise-or-data-leakage\/\"  data-wpil-monitor-id=\"63804\">System compromise<\/a>, potential data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3968423958\" 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>Mattermost | 10.5.x <= 10.5.5\nMattermost | 9.11.x <= 9.11.15\nMattermost | 10.8.x <= 10.8.0\nMattermost | 10.7.x <= 10.7.2\nMattermost | 10.6.x <= 10.6.5\n\n<strong>How the Exploit Works<\/strong><\/p>\n<p>The exploit leverages the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49126-critical-reflected-xss-vulnerability-in-visionatrix-ai-media-processing-tool\/\"  data-wpil-monitor-id=\"63599\">vulnerability in Mattermost&#8217;s archive extraction process<\/a>. An authenticated user can upload an archive with a malicious filename containing <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-39473-path-traversal-vulnerability-in-webgeniuslab-seofy-core\/\"  data-wpil-monitor-id=\"62023\">path traversal<\/a> sequences. Mattermost&#8217;s failure to sanitize these filenames <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-41666-watchdog-file-replacement-vulnerability-allowing-remote-access-and-control\/\"  data-wpil-monitor-id=\"66647\">allows the file<\/a> to be written to any location on the filesystem. This capability can lead to remote code execution if a malicious <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-5485-a-critical-vulnerability-pertaining-to-user-name-enumeration-in-web-management-interfaces\/\"  data-wpil-monitor-id=\"61653\">user manages<\/a> to place an executable file in a directory where it can be run automatically or by a privileged user.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p>\n<p>Here&#8217;s a conceptual example of how an <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-48860-exploiting-backup-archives-to-gain-remote-access-in-ctrlx-os\/\"  data-wpil-monitor-id=\"81412\">exploit using a malicious archive<\/a> might work:<\/p><div id=\"ameeb-3274674015\" 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<pre><code class=\"\" data-line=\"\">POST \/api\/v4\/files HTTP\/1.1\nHost: mattermost.example.com\nAuthorization: Bearer &lt;access-token&gt;\nContent-Type: multipart\/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW\n------WebKitFormBoundary7MA4YWxkTrZu0gW\nContent-Disposition: form-data; name=&quot;files&quot;; filename=&quot;..\/..\/..\/etc\/cron.d\/malicious&quot;\nContent-Type: application\/gzip\n{ binary data }\n------WebKitFormBoundary7MA4YWxkTrZu0gW--<\/code><\/pre>\n<p>In this example, an HTTP POST request is made to the Mattermost file upload <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-49181-unauthorized-api-endpoint-access-leading-to-denial-of-service-and-data-leakage\/\"  data-wpil-monitor-id=\"61677\">API endpoint<\/a>. The archive contains a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-39475-path-traversal-vulnerability-leading-to-php-local-file-inclusion-in-frenify-arlo\/\"  data-wpil-monitor-id=\"62027\">file with a path traversal<\/a> sequence in the filename (`..\/..\/..\/etc\/cron.d\/malicious`). This file could contain instructions for a cron job that executes a malicious script, potentially <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47167-microsoft-office-type-confusion-vulnerability-leading-to-unauthorized-local-code-execution\/\"  data-wpil-monitor-id=\"61756\">leading to remote code<\/a> execution.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The vulnerability in focus, CVE-2025-4981, presents a significant security threat to a host of Mattermost versions. As a widely used open-source, self-hosted online chat service, Mattermost has a broad range of commercial and non-commercial users globally. The vulnerability arises from the failure of these versions to sanitize filenames in the archive extractor, thereby providing [&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":[80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-55137","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-rce"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/55137","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=55137"}],"version-history":[{"count":12,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/55137\/revisions"}],"predecessor-version":[{"id":80854,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/55137\/revisions\/80854"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=55137"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=55137"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=55137"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=55137"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=55137"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=55137"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=55137"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=55137"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=55137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}