CVE-2021-32693 : Security Advisory and Response

A vulnerability in Symfony versions 5.3.0 to 5.3.2 allowed authentication granted with multiple firewalls, potentially leading to improper authentication.

Understanding CVE-2021-32693

This CVE highlights a security flaw in the Symfony PHP framework regarding firewall authentication.

What is CVE-2021-32693?

Symfony versions between 5.3.0 and 5.3.2 were affected by a vulnerability that allowed authenticated tokens from one firewall to be accessed by all others, potentially causing unauthorized access.

The Impact of CVE-2021-32693

The vulnerability could lead to compromised confidentiality and integrity due to unauthorized users gaining access across different parts of the application.

Technical Details of CVE-2021-32693

The CVSS score for this CVE is 6.8, indicating a medium severity vulnerability with high confidentiality and integrity impact.

Vulnerability Description

The flaw allowed tokens authenticated by one firewall to be used across multiple firewalls, compromising the security of the application.

Affected Systems and Versions

Symfony versions >= 5.3.0 and < 5.3.2 are affected by this vulnerability.

Exploitation Mechanism

When an application defined multiple firewalls, a user authenticated on one part could be considered authenticated on the rest of the application.

Mitigation and Prevention

To address CVE-2021-32693, immediate steps must be taken to secure Symfony applications and prevent unauthorized access.

Immediate Steps to Take

Update Symfony to version 5.3.2 or apply the patch provided to ensure that authenticated tokens are only available for the generating firewall.

Long-Term Security Practices

Regularly monitor security advisories related to Symfony and implement security best practices to mitigate future vulnerabilities.

Patching and Updates

Stay informed about security updates for Symfony to protect your applications from potential security threats.