CVE-2020-2101 Explained : Impact and Mitigation

Jenkins 2.218 and earlier, LTS 2.204.1 and earlier did not use a constant-time comparison function for validating connection secrets, potentially allowing an attacker to exploit a timing attack to obtain the secret.

Understanding CVE-2020-2101

This CVE involves a vulnerability in Jenkins that could be exploited by attackers to obtain sensitive information through a timing attack.

What is CVE-2020-2101?

CVE-2020-2101 is a security vulnerability in Jenkins versions 2.218 and earlier, as well as LTS 2.204.1 and earlier. It arises from the lack of a constant-time comparison function for validating connection secrets, making it susceptible to timing attacks.

The Impact of CVE-2020-2101

The vulnerability could allow malicious actors to extract sensitive connection secrets by leveraging timing discrepancies, potentially compromising the security and confidentiality of the affected systems.

Technical Details of CVE-2020-2101

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

Jenkins versions 2.218 and earlier, as well as LTS 2.204.1 and earlier, lack a constant-time comparison function for validating connection secrets, enabling attackers to exploit timing attacks to retrieve these secrets.

Affected Systems and Versions

Product: Jenkins
Vendor: Jenkins project
Vulnerable Versions:
Jenkins <= 2.218
LTS <= 2.204.1

Exploitation Mechanism

Attackers can exploit the vulnerability by leveraging timing discrepancies in the comparison function used for validating connection secrets, allowing them to extract sensitive information.

Mitigation and Prevention

Protecting systems from CVE-2020-2101 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Jenkins to a patched version that includes a constant-time comparison function for connection secret validation.
Monitor system logs for any suspicious activities that could indicate exploitation attempts.

Long-Term Security Practices

Implement regular security audits and assessments to identify and address vulnerabilities promptly.
Educate users and administrators on secure coding practices and the importance of timely software updates.

Patching and Updates

Apply security patches provided by Jenkins project to address the vulnerability and enhance system security.