{"id":11337,"date":"2025-10-20T11:38:01","date_gmt":"2025-10-20T04:38:01","guid":{"rendered":"https:\/\/infosec.new88088.net\/?p=11337"},"modified":"2026-06-25T09:55:58","modified_gmt":"2026-06-25T02:55:58","slug":"a-vulnerability-to-linux-pam-authentication-systems-that-may-allow-users-to-gain-root-privileges","status":"publish","type":"post","link":"https:\/\/infosec.new88088.net\/en\/2025\/10\/20\/a-vulnerability-to-linux-pam-authentication-systems-that-may-allow-users-to-gain-root-privileges\/","title":{"rendered":"A vulnerability to Linux-PAM authentication systems that may allow users to gain root privileges"},"content":{"rendered":"

A security flaw has been announced in the well-known authentication modules Pluggable Authentication Modules (Linux-PAM). Codenamed CVE-2025-8941, this vulnerability gives users local access that can be exploited to take full control of the system through a series of sophisticated techniques such as Symbolic Link Attack and Disputes Conditions.<\/b><\/p>\n

\"1760942587457.png\"<\/a>\u200b<\/div>\n

While remote mining is not possible, in a multi-user environment or server system, the risk of exploiting this vulnerability to leak data, install malicious code, or destroy the system is possible and is causing security “freeze”.<\/p>\n

The vulnerability was discovered and announced by security experts from the Ameeba Security team. They analyzed the pam_namespace module (a component in Linux-PAM responsible for creating separate namespace for user sessions).<\/p>\n

The original goal of this module was to protect the user by separating the work environment, but inadvertently revealed a fatal flaw: incorrect handling of user-controlled paths, resulting in the insertion of symlinks and the exploitation of the runtime condition when the system creates folders.<\/p>\n

2. How to exploit<\/h4>\n

Imagine a normal user on a Linux system making a symbolic link from his \/ her directory to the \/ root directory (which is only available to the system administrator):<\/p>\n

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ln – s \/root \/tmp\/victim\/symlink<\/div>\n
Click to expand…<\/a><\/div>\n<\/div>\n<\/blockquote>\n

When the system is performing the creation of an isolation folder for this user, if the attacker is timed correctly, the system will inadvertently create a folder inside \/ root. At this point, through permission adjustment, users can usually take full control of the system:<\/p>\n

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chmod 777 \/root<\/div>\n
Click to expand…<\/a><\/div>\n<\/div>\n<\/blockquote>\n

While the actual exploit requires high-tech and complex scripts, the end result is root access (the highest access in Unix\/Linux). Once achieved, the attacker may:<\/p>\n