CVE-2019-11762 : Vulnerability Insights and Analysis

A security vulnerability affecting Firefox, Thunderbird, and Firefox ESR versions before specific releases.

Understanding CVE-2019-11762

This CVE involves a potential security issue in Firefox, Thunderbird, and Firefox ESR versions.

What is CVE-2019-11762?

In scenarios where two documents from the same source modify document.domain to become cross-origin, a vulnerability exists that could allow them to invoke arbitrary DOM methods, getters, and setters on the window that is now cross-origin.

The Impact of CVE-2019-11762

This vulnerability affects versions of Firefox prior to 70, Thunderbird prior to 68.2, and Firefox ESR prior to 68.2.

Technical Details of CVE-2019-11762

Details about the vulnerability and affected systems.

Vulnerability Description

If two same-origin documents set document.domain differently to become cross-origin, it was possible for them to call arbitrary DOM methods, getters, and setters on the now-cross-origin window.

Affected Systems and Versions

Firefox versions before 70
Thunderbird versions before 68.2
Firefox ESR versions before 68.2

Exploitation Mechanism

The vulnerability arises when two documents from the same source modify document.domain to become cross-origin, enabling them to invoke arbitrary DOM methods, getters, and setters on the now cross-origin window.

Mitigation and Prevention

Steps to mitigate and prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Firefox, Thunderbird, and Firefox ESR to versions 70, 68.2, and 68.2 respectively.
Avoid scenarios where two documents from the same source modify document.domain.

Long-Term Security Practices

Regularly update software to the latest versions.
Implement proper origin isolation practices to prevent cross-origin vulnerabilities.

Patching and Updates

Apply patches provided by Mozilla for Firefox, Thunderbird, and Firefox ESR to address this vulnerability.