CVE-2018-5143 : Security Advisory and Response

A vulnerability in Firefox versions prior to 59 could allow for the execution of cross-site scripting (XSS) attacks when a "javascript:" URL with an embedded tab character is pasted into the address bar.

Understanding CVE-2018-5143

What is CVE-2018-5143?

This CVE refers to a security flaw in Firefox that enables the execution of XSS attacks by not removing the protocol from a "javascript:" URL containing a tab character when pasted into the address bar.

The Impact of CVE-2018-5143

Users could unknowingly trigger XSS attacks on themselves by pasting malicious "javascript:" URLs with tabs, leading to potential security breaches and data compromise.

Technical Details of CVE-2018-5143

Vulnerability Description

Firefox versions prior to 59 do not strip the protocol from "javascript:" URLs with tabs, allowing for the execution of embedded scripts.

Affected Systems and Versions

Product: Firefox
Vendor: Mozilla
Versions Affected: < 59

Exploitation Mechanism

By pasting a "javascript:" URL with a tab character into the address bar, users can inadvertently trigger the execution of embedded scripts, facilitating XSS attacks.

Mitigation and Prevention

Immediate Steps to Take

Update Firefox to version 59 or above to mitigate the vulnerability.
Avoid pasting unknown or suspicious URLs into the address bar.

Long-Term Security Practices

Educate users on safe browsing habits and the risks associated with executing scripts from untrusted sources.

Patching and Updates

Regularly check for and apply security updates for Firefox to address known vulnerabilities.