CVE-2017-5180 : What You Need to Know

Firejail versions earlier than 0.9.44.4 and 0.9.38.x LTS versions prior to 0.9.38.8 LTS have a vulnerability that allows local users to conduct sandbox-escape attacks through specific vectors.

Understanding CVE-2017-5180

What is CVE-2017-5180?

CVE-2017-5180 is a vulnerability in Firejail versions that fail to account for a specific case, enabling local users to bypass security measures and execute sandbox-escape attacks.

The Impact of CVE-2017-5180

This vulnerability allows local users to escalate privileges and potentially compromise the system through sandbox-escape attacks.

Technical Details of CVE-2017-5180

Vulnerability Description

Firejail versions before 0.9.44.4 and 0.9.38.x LTS before 0.9.38.8 LTS do not properly handle a specific case, leading to a security flaw that can be exploited by local users.

Affected Systems and Versions

Firejail versions prior to 0.9.44.4
Firejail 0.9.38.x LTS versions before 0.9.38.8 LTS

Exploitation Mechanism

The vulnerability arises due to a failure to consider the .Xauthority case while attempting to block access to user files with an effective user ID (euid) of zero. Local users can exploit this flaw using a symlink and the --private option.

Mitigation and Prevention

Immediate Steps to Take

Update Firejail to version 0.9.44.4 or later.
Apply patches provided by the vendor to address the vulnerability.

Long-Term Security Practices

Regularly monitor for security advisories and updates from Firejail.
Implement the principle of least privilege to restrict user access and mitigate potential risks.

Patching and Updates

Keep Firejail up to date with the latest security patches and versions to prevent exploitation of known vulnerabilities.