CVE-2017-5940 : What You Need to Know

Firejail versions prior to 0.9.44.6 and 0.9.38.x LTS versions prior to 0.9.38.10 LTS have a vulnerability that allows local users to execute sandbox-escape attacks. This flaw arises from inadequate handling of dotfile scenarios, enabling unauthorized access to user files with an effective user ID of zero.

Understanding CVE-2017-5940

This CVE identifies a security vulnerability in Firejail versions that can be exploited by local users to bypass sandbox restrictions.

What is CVE-2017-5940?

CVE-2017-5940 is a vulnerability in Firejail versions prior to 0.9.44.6 and 0.9.38.x LTS versions prior to 0.9.38.10 LTS. It allows local users to execute sandbox-escape attacks by leveraging symlink and the --private option.

The Impact of CVE-2017-5940

The vulnerability enables local users to bypass security restrictions and gain unauthorized access to user files with an effective user ID of zero, potentially leading to further system compromise.

Technical Details of CVE-2017-5940

Firejail versions prior to 0.9.44.6 and 0.9.38.x LTS versions prior to 0.9.38.10 LTS are affected by this vulnerability.

Vulnerability Description

The flaw arises from incomplete handling of dotfile scenarios, allowing local users to conduct sandbox-escape attacks using a symlink and the --private option.

Affected Systems and Versions

Firejail versions prior to 0.9.44.6
Firejail 0.9.38.x LTS versions prior to 0.9.38.10 LTS

Exploitation Mechanism

Local users can exploit this vulnerability by employing a symlink and the --private option to execute sandbox-escape attacks.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks posed by CVE-2017-5940.

Immediate Steps to Take

Update Firejail to version 0.9.44.6 or later to address the vulnerability.
Monitor system logs for any suspicious activities.

Long-Term Security Practices

Regularly update software and apply security patches.
Implement the principle of least privilege to restrict user access.

Patching and Updates

Apply the latest patches and updates provided by Firejail to ensure system security.