CVE-2021-41246 Explained : Impact and Mitigation

Express OpenID Connect is vulnerable to session fixation due to a flaw in session id regeneration during user login, leading to potential security risks.

Understanding CVE-2021-41246

Express OpenID Connect middleware for Express web apps using OpenID Connect versions prior to

2.5.1

are susceptible to session fixation vulnerabilities.

What is CVE-2021-41246?

Express OpenID Connect allows sign-on for Express web apps. Versions before

2.5.1

fail to regenerate the session id and cookie upon user login, exposing the application to session fixation threats.

The Impact of CVE-2021-41246

The vulnerability has a CVSS base score of 4.6, with medium severity. It requires user interaction and may compromise confidentiality and integrity, posing session fixation risks.

Technical Details of CVE-2021-41246

Express OpenID Connect < 2.5.1 fails to refresh session id and cookie after user login, potentially leading to session fixation attacks.

Vulnerability Description

Express OpenID Connect versions <= 2.5.1 do not regenerate the session id, risking session fixation vulnerabilities. Version

2.5.2

addresses this issue.

Affected Systems and Versions

Product: express-openid-connect
Vendor: auth0
Versions affected: >= 2.3.0, < 2.5.2

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Scope: Unchanged

Mitigation and Prevention

Immediate action is essential to mitigate the risk of session fixation. Ensure long-term security through continuous vigilance and prompt patching.

Immediate Steps to Take

Upgrade to version

2.5.2

or later to apply the patch.
Monitor user sessions for anomalies or unauthorized access.
Implement strong session handling mechanisms.

Long-Term Security Practices

Regularly review and update security configurations.
Conduct thorough security assessments, including session management.

Patching and Updates

Apply security updates promptly.