CVE-2021-31866 Explained : Impact and Mitigation

Redmine before versions 4.0.9 and 4.1.x before 4.1.3 has a vulnerability that allows attackers to determine internal authentication keys through timing differences in string operations.

Understanding CVE-2021-31866

This CVE identifies a security flaw in Redmine versions 4.0.9 and 4.1.x that can be exploited to expose sensitive authentication keys.

What is CVE-2021-31866?

The vulnerability in Redmine enables a malicious actor to discern valuable internal authentication keys by analyzing timing variations in string comparison operations occurring within SysController and MailHandlerController.

The Impact of CVE-2021-31866

Exploitation of this vulnerability can lead to unauthorized access to sensitive system information and potentially compromise the security and integrity of affected Redmine instances.

Technical Details of CVE-2021-31866

Below are specific technical details related to CVE-2021-31866:

Vulnerability Description

The flaw in Redmine versions before 4.0.9 and 4.1.x before 4.1.3 allows threat actors to deduce internal authentication keys by observing timing discrepancies in string comparison operations within SysController and MailHandlerController.

Affected Systems and Versions

Redmine instances running versions 4.0.9 and 4.1.x up to 4.1.3 are susceptible to this security vulnerability.

Exploitation Mechanism

Attackers can exploit the timing differences in string operations during authentication processes to decipher internal authentication keys, compromising system security.

Mitigation and Prevention

To address CVE-2021-31866 and enhance the security of Redmine deployments, consider the following actionable steps:

Immediate Steps to Take

Upgrade affected Redmine instances to version 4.0.9 or higher, or 4.1.3 or above to mitigate the vulnerability.
Monitor system logs and network traffic for any suspicious activities that may indicate exploitation attempts.

Long-Term Security Practices

Regularly audit and review the security configurations of Redmine installations to identify and address potential vulnerabilities proactively.
Implement strong access controls and authentication mechanisms to restrict unauthorized access to critical system components.

Patching and Updates

Stay informed about security updates and advisories from Redmine to promptly apply patches and fixes that address known vulnerabilities.