CVE-2019-11761 Explained : Impact and Mitigation

A vulnerability in Firefox, Thunderbird, and Firefox ESR versions before specific releases allowed unintended access to a privileged JSONView object.

Understanding CVE-2019-11761

What is CVE-2019-11761?

Through a crafted data URI structure, attackers could access a cloned JSONView object, bypassing security measures in Firefox, Thunderbird, and Firefox ESR.

The Impact of CVE-2019-11761

Exposing the JSONView object had minimal immediate consequences but posed a risk by circumventing established security layers.

Technical Details of CVE-2019-11761

Vulnerability Description

By exploiting a data URI form, unauthorized access to a privileged JSONView object was achievable in affected versions.

Affected Systems and Versions

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

Exploitation Mechanism

Attackers could use a crafted data URI structure to gain access to the JSONView object, potentially bypassing security controls.

Mitigation and Prevention

Immediate Steps to Take

Update Firefox, Thunderbird, and Firefox ESR to versions 70, 68.2, and 68.2 respectively.
Avoid clicking on suspicious links or downloading files from untrusted sources.

Long-Term Security Practices

Regularly update software to the latest versions to patch known vulnerabilities.
Implement security best practices to prevent unauthorized access to sensitive objects.

Patching and Updates

Apply security patches provided by Mozilla promptly to address the vulnerability.