{"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":"CVE-2025-4981: Critical File Extraction Vulnerability in Mattermost Leading to Potential Remote Code Execution<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

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<\/a> to sanitize filenames in the archive extractor, thereby providing authenticated users the potential to write files anywhere on the filesystem. This vulnerability can lead<\/a> to remote code execution and consequently, a considerable system compromise or data leakage.
\nGiven the severity of the potential impact, understanding this 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 integrity of these systems<\/a>.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-4981
\nSeverity: Critical (CVSS score 9.9)
\nAttack Vector: Network
\nPrivileges Required: User
\nUser Interaction: Required
\nImpact: System compromise<\/a>, potential data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

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\nHow the Exploit Works<\/strong><\/p>\n

The exploit leverages the vulnerability in Mattermost’s archive extraction process<\/a>. An authenticated user can upload an archive with a malicious filename containing path traversal<\/a> sequences. Mattermost’s failure to sanitize these filenames allows the file<\/a> to be written to any location on the filesystem. This capability can lead to remote code execution if a malicious user manages<\/a> to place an executable file in a directory where it can be run automatically or by a privileged user.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Here’s a conceptual example of how an exploit using a malicious archive<\/a> might work:<\/p>\n

POST \/api\/v4\/files HTTP\/1.1\nHost: mattermost.example.com\nAuthorization: Bearer \nContent-Type: multipart\/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW\n------WebKitFormBoundary7MA4YWxkTrZu0gW\nContent-Disposition: form-data; name=\"files\"; filename=\"..\/..\/..\/etc\/cron.d\/malicious\"\nContent-Type: application\/gzip\n{ binary data }\n------WebKitFormBoundary7MA4YWxkTrZu0gW--<\/code><\/pre>\n
In this example, an HTTP POST request is made to the Mattermost file upload API endpoint<\/a>. The archive contains a 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 leading to remote code<\/a> execution.<\/p>\n","protected":false},"excerpt":{"rendered":"
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 […]<\/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,"_monsterinsights_skip_tracking":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":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t