CVE-2021-21700 : What You Need to Know

Jenkins Scriptler Plugin 3.3 and earlier versions are affected by a stored cross-site scripting (XSS) vulnerability. Attackers can exploit this issue by creating malicious Scriptler scripts.

Understanding CVE-2021-21700

This CVE details a security vulnerability in the Jenkins Scriptler Plugin, allowing stored XSS attacks.

What is CVE-2021-21700?

CVE-2021-21700 affects Jenkins Scriptler Plugin versions 3.3 and earlier. The vulnerability arises due to the lack of proper script name escaping on the UI, potentially leading to XSS attacks.

The Impact of CVE-2021-21700

The security flaw enables attackers to execute malicious scripts through the vulnerability, posing a risk to the integrity and security of Jenkins instances.

Technical Details of CVE-2021-21700

The vulnerability is caused by the failure to escape script names properly on the Jenkins Scriptler Plugin UI, allowing attackers to inject and execute malicious scripts.

Vulnerability Description

Jenkins Scriptler Plugin 3.3 and earlier versions are susceptible to stored cross-site scripting (XSS) attacks, as the script names are not sanitized on the deletion confirmation UI.

Affected Systems and Versions

The vulnerability impacts Jenkins Scriptler Plugin versions up to and including 3.3.

Exploitation Mechanism

Attackers who can create Scriptler scripts have the capability to exploit this vulnerability to launch stored cross-site scripting attacks.

Mitigation and Prevention

Users and administrators should take immediate action to mitigate the risks posed by CVE-2021-21700.

Immediate Steps to Take

Update Jenkins Scriptler Plugin to a version that addresses the XSS vulnerability. Implement input validation and output encoding to prevent script injection.

Long-Term Security Practices

Regularly check for security updates and patches for Jenkins plugins. Educate users on safe scripting practices and encourage adherence to security best practices.

Patching and Updates

Ensure that Jenkins and its associated plugins are regularly updated to the latest secure versions to prevent exploitation of known vulnerabilities.