CVE-2018-12398 : Security Advisory and Response

A vulnerability in Firefox versions prior to 63 allows for the injection of stylesheets and bypassing Content Security Policy (CSP) through reflected URLs in certain resource URIs.

Understanding CVE-2018-12398

This CVE involves a security issue in Firefox versions before 63 that enables the injection of stylesheets and circumvention of CSP by utilizing reflected URLs in specific resource URIs.

What is CVE-2018-12398?

By exploiting reflected URLs in resource URIs like chrome:, attackers can inject stylesheets and bypass CSP in Firefox versions less than 63.

The Impact of CVE-2018-12398

This vulnerability poses a risk of allowing malicious actors to inject unauthorized stylesheets and bypass CSP restrictions, potentially leading to unauthorized access or data manipulation.

Technical Details of CVE-2018-12398

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability allows for the injection of stylesheets and bypassing CSP by leveraging reflected URLs in specific resource URIs, such as chrome:.

Affected Systems and Versions

Product: Firefox
Vendor: Mozilla
Versions Affected: < 63

Exploitation Mechanism

Attackers can exploit this vulnerability by utilizing reflected URLs in certain resource URIs to inject stylesheets and bypass CSP in Firefox versions prior to 63.

Mitigation and Prevention

Protecting systems from CVE-2018-12398 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Firefox to version 63 or higher to mitigate the vulnerability.
Implement strict Content Security Policies to limit the risk of stylesheet injection.

Long-Term Security Practices

Regularly monitor and update browsers and security configurations.
Educate users on safe browsing practices to prevent exploitation of similar vulnerabilities.

Patching and Updates

Apply security patches and updates provided by Mozilla to address the vulnerability and enhance browser security.