CVE-2017-7761 Explained : Impact and Mitigation

A vulnerability in Mozilla Maintenance Service allows for file deletion and privilege escalation through the 'helper.exe' application.

Understanding CVE-2017-7761

This CVE affects Firefox ESR versions before 52.2 and Firefox versions prior to 54.

What is CVE-2017-7761?

The 'helper.exe' application of the Mozilla Maintenance Service creates a temporary directory that can be written to by non-privileged users. By using a junction, the service can delete protected files in the designated directory due to its elevated permissions. This vulnerability requires local system access and impacts only Windows operating systems.

The Impact of CVE-2017-7761

Allows unauthorized users to delete protected files
Enables privilege escalation through the Mozilla Maintenance Service
Specifically affects Windows operating systems

Technical Details of CVE-2017-7761

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows for file deletion and privilege escalation through the 'helper.exe' application of the Mozilla Maintenance Service.

Affected Systems and Versions

Products: Firefox ESR, Firefox
Vendor: Mozilla
Affected Versions: Firefox ESR < 52.2, Firefox < 54

Exploitation Mechanism

The attack involves creating a junction, a symbolic link, to delete protected files in the target directory of the junction using the Mozilla Maintenance Service.

Mitigation and Prevention

Protect your systems from CVE-2017-7761 with these mitigation strategies.

Immediate Steps to Take

Update Firefox ESR to version 52.2 or newer
Update Firefox to version 54 or newer
Monitor system for any suspicious activities

Long-Term Security Practices

Implement the principle of least privilege for user accounts
Regularly review and update security configurations

Patching and Updates

Apply security patches provided by Mozilla
Stay informed about security advisories and updates from Mozilla