CVE-2020-6813 : Security Advisory and Response

This CVE-2020-6813 article provides insights into a vulnerability affecting Firefox versions below 74, allowing attackers to inject arbitrary styles by bypassing Content Security Policy's nonce feature.

Understanding CVE-2020-6813

This section delves into the details of the vulnerability and its impact.

What is CVE-2020-6813?

CVE-2020-6813 is a security vulnerability in Firefox versions less than 74 that enables attackers to inject arbitrary styles by exploiting the @import statement in CSS blocks, circumventing the intended security measures of Content Security Policy.

The Impact of CVE-2020-6813

The vulnerability poses a risk of allowing malicious actors to bypass Content Security Policy protections and inject unauthorized styles into web pages, potentially leading to various security threats.

Technical Details of CVE-2020-6813

Explore the technical aspects of the vulnerability in this section.

Vulnerability Description

The flaw arises when using the nonce feature of Content Security Policy to protect CSS blocks, as the @import statement within the CSS block can be manipulated by attackers to introduce unauthorized styles, undermining the security controls.

Affected Systems and Versions

Affected Product: Firefox
Vendor: Mozilla
Affected Versions: Less than 74

Exploitation Mechanism

The vulnerability allows threat actors to exploit the @import statement in CSS blocks to inject arbitrary styles, evading the restrictions imposed by the Content Security Policy nonce feature.

Mitigation and Prevention

Discover the steps to mitigate and prevent the exploitation of CVE-2020-6813.

Immediate Steps to Take

Users should update Firefox to version 74 or above to mitigate the vulnerability.
Implement strict Content Security Policies to limit the impact of CSS injection attacks.

Long-Term Security Practices

Regularly monitor security advisories from Mozilla and apply patches promptly.
Conduct security assessments to identify and address vulnerabilities in web applications.

Patching and Updates

Mozilla has released patches addressing this vulnerability in Firefox versions 74 and later.
Ensure timely installation of updates to protect systems from potential exploits.