CVE-2021-39940 : What You Need to Know
Discover the impact and mitigation strategies for CVE-2021-39940 affecting GitLab versions. Learn about the vulnerability, its technical details, and steps for prevention.
GitLab has disclosed a vulnerability, affecting multiple versions, that exposes its Maven Package registry to a regular expression denial of service attack. Learn more about the impact, technical details, and mitigation strategies.
Understanding CVE-2021-39940
This section provides insights into the CVE-2021-39940 vulnerability identified in GitLab.
What is CVE-2021-39940?
An issue in GitLab CE/EE versions between 13.2 and 14.5.2 could lead to a denial of service due to regex vulnerabilities in the Maven Package registry.
The Impact of CVE-2021-39940
The vulnerability has a CVSS base score of 4.3, indicating a medium severity level. Specific details include:
- Attack Complexity: Low
- Attack Vector: Network
- Availability Impact: Low
- Confidentiality Impact: None
- Integrity Impact: None
- Privileges Required: Low
- User Interaction: None
- Scope: Unchanged
Technical Details of CVE-2021-39940
Explore the specific technical aspects of the CVE-2021-39940 vulnerability.
Vulnerability Description
The issue in GitLab exposes versions between 13.2 and 14.5.2 to regex denial of service, primarily impacting the Maven Package registry.
Affected Systems and Versions
Multiple versions of GitLab are affected, including:
- Versions >=14.5 and <14.5.2
- Versions >=14.4 and <14.4.4
- Versions >=13.2 and <14.3.6
Exploitation Mechanism
Attackers can exploit this vulnerability by sending a specifically crafted string to the GitLab Maven Package registry.
Mitigation and Prevention
Discover the steps to mitigate and prevent the CVE-2021-39940 vulnerability.
Immediate Steps to Take
- Update GitLab to versions 14.3.6, 14.4.4, or 14.5.2 to patch the vulnerability.
- Monitor system logs for any potential denial-of-service attempts.
Long-Term Security Practices
- Conduct regular security assessments and audits to identify vulnerabilities.
- Educate teams on secure coding practices and regex validation.
Patching and Updates
Ensure timely application of GitLab updates and security patches to address known vulnerabilities.