CVE-2021-42136 Explained : Impact and Mitigation

A stored Cross-Site Scripting (XSS) vulnerability in the Missing Data Codes functionality of REDCap before 11.4.0 allows remote attackers to execute JavaScript code in the client's browser and potentially escalate privileges.

Understanding CVE-2021-42136

What is CVE-2021-42136?

This CVE refers to a stored Cross-Site Scripting (XSS) vulnerability in REDCap, enabling attackers to run malicious JavaScript in a victim's browser to execute Cross-Site Request Forgery attacks.

The Impact of CVE-2021-42136

The vulnerability permits remote attackers to execute JavaScript code as a Missing Data Code value, possibly leading to privilege escalation to administrator level.

Technical Details of CVE-2021-42136

Vulnerability Description

Vulnerability Type: Stored Cross-Site Scripting (XSS)
Affected Component: Missing Data Codes functionality in REDCap

Affected Systems and Versions

Systems: REDCap before version 11.4.0

Exploitation Mechanism

Attackers store malicious code as a Missing Data Code value
The stored code is executed in the victim's browser, potentially allowing for Cross-Site Request Forgery attacks

Mitigation and Prevention

Immediate Steps to Take

Upgrade REDCap to version 11.4.0 or later to mitigate the vulnerability
Regularly monitor and sanitize user inputs to prevent XSS attacks

Long-Term Security Practices

Conduct security training for developers on secure coding practices
Implement Content Security Policy (CSP) headers to reduce XSS risks

Patching and Updates

Apply security patches promptly to address known vulnerabilities in third-party components