CVE-2020-26951 Explained : Impact and Mitigation

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Understanding CVE-2020-26951

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization.

What is CVE-2020-26951?

This CVE refers to a vulnerability in Firefox, Firefox ESR, and Thunderbird that could allow an attacker to bypass the built-in sanitizer by exploiting an XSS vulnerability in privileged internal pages.

The Impact of CVE-2020-26951

The vulnerability could lead to the execution of malicious code by an attacker with the capability to exploit an XSS vulnerability in privileged internal pages.

Technical Details of CVE-2020-26951

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization.

Vulnerability Description

Parsing mismatches in Firefox's SVG code could confuse and bypass the security sanitizer for chrome privileged code.

Affected Systems and Versions

Firefox < 83
Firefox ESR < 78.5
Thunderbird < 78.5

Exploitation Mechanism

An attacker with the ability to exploit an XSS vulnerability in privileged internal pages could use this vulnerability to bypass the built-in sanitizer.

Mitigation and Prevention

Immediate Steps to Take:

Update Firefox, Firefox ESR, and Thunderbird to versions 83, 78.5, and 78.5 respectively.

Long-Term Security Practices:

Regularly update browsers and email clients to the latest versions.

Patching and Updates:

Apply patches provided by Mozilla to address this vulnerability.