CVE-2017-5389 : Exploit Details and Defense Strategies

A security vulnerability in Mozilla Firefox versions prior to 51 allows malicious extensions to install additional extensions without user consent.

Understanding CVE-2017-5389

What is CVE-2017-5389?

WebExtensions in Firefox can abuse the "mozAddonManager" API to manipulate CSP headers and load scripts from harmful sites, enabling unauthorized installation of extensions.

The Impact of CVE-2017-5389

This vulnerability permits malicious extensions to install supplementary extensions without explicit user approval, compromising system security.

Technical Details of CVE-2017-5389

Vulnerability Description

WebExtensions in Firefox < 51 can exploit the "mozAddonManager" API to redirect script loads to malicious sites, facilitating unauthorized extension installations.

Affected Systems and Versions

Product: Firefox
Vendor: Mozilla
Versions Affected: < 51

Exploitation Mechanism

Malicious extensions modify CSP headers and use host requests to load scripts from harmful sites, allowing unauthorized extension installations.

Mitigation and Prevention

Immediate Steps to Take

Update Firefox to version 51 or higher to mitigate the vulnerability.
Regularly review and remove suspicious extensions from the browser.

Long-Term Security Practices

Be cautious when installing browser extensions and only use trusted sources.
Implement strict CSP policies to prevent unauthorized script execution.

Patching and Updates

Stay informed about security advisories from Mozilla and promptly apply recommended patches and updates.