CVE-2021-39890 : What You Need to Know

CVE-2021-39890, discovered in GitLab, allows bypassing 2FA for LDAP users and accessing specific pages via Basic Authentication.

Understanding CVE-2021-39890

This CVE highlights a vulnerability in GitLab versions above 14.1.1 that enables bypassing 2FA for LDAP users.

What is CVE-2021-39890?

The vulnerability permits access to certain pages using Basic Authentication, impacting GitLab versions >=14.1.1.

The Impact of CVE-2021-39890

The CVSS score for this vulnerability is 3.1 (Low severity) with an attack complexity of HIGH over a NETWORK vector.

Technical Details of CVE-2021-39890

The technical aspects of this CVE are crucial for understanding its implications.

Vulnerability Description

The flaw enables LDAP user 2FA bypass, allowing unauthorized access to specific pages through Basic Authentication.

Affected Systems and Versions

Product: GitLab
Versions Affected:
=14.3, <14.3.1

=14.2, <14.2.5

=14.1.1, <14.1.7

Exploitation Mechanism

Attack Vector: NETWORK
Attack Complexity: HIGH
Privileges Required: LOW

Mitigation and Prevention

It's vital to take immediate action to mitigate the risks posed by CVE-2021-39890.

Immediate Steps to Take

Upgrade affected GitLab instances to versions above 14.3.1, 14.2.5, and 14.1.7.
Implement stricter access controls and consider disabling LDAP authentication.

Long-Term Security Practices

Regularly monitor and audit user access and authentication mechanisms.
Stay informed about security updates and patches released by GitLab.

Patching and Updates

Stay updated with GitLab's security advisories and apply patches promptly.