CVE-2021-44141 Explained : Impact and Mitigation

A vulnerability in versions of Samba prior to 4.15.5 allows a malicious client to exploit server symlinks to access files not intended to be shared.

Understanding CVE-2021-44141

What is CVE-2021-44141?

This CVE refers to a security vulnerability in Samba versions before 4.15.5 that enables a malicious client to use server symlinks to check for the existence of files or directories that are not shared through the server definition.

The Impact of CVE-2021-44141

Exploiting this vulnerability requires SMB1 with unix extensions enabled and could lead to unauthorized access to sensitive files on the server.

Technical Details of CVE-2021-44141

Vulnerability Description

The vulnerability allows an attacker to bypass file access restrictions by using server symlinks with SMB1 enabled.

Affected Systems and Versions

Vendor: n/a
Product: Samba
Affected Versions: All versions of Samba prior to 4.15.5

Exploitation Mechanism

The exploit leverages server symlinks to gain access to files or directories not meant to be shared through the server shares.

Mitigation and Prevention

Immediate Steps to Take

Disable SMB1 with unix extensions if not needed.
Update Samba to version 4.15.5 or later.

Long-Term Security Practices

Regularly monitor and audit symlink usage.
Implement access controls to limit symlink abuse.

Patching and Updates

Apply the latest security patches from Samba to ensure the vulnerability is addressed effectively.