CVE-2021-41688 : Security Advisory and Response

DCMTK through 3.6.6 is vulnerable to a memory free issue that can lead to a DoS attack due to improper handling of freed memory addresses.

Understanding CVE-2021-41688

What is CVE-2021-41688?

DCMTK through version 3.6.6 fails to manage memory deallocation correctly, resulting in freed memory addresses still being referenced. Exploiting this vulnerability can trigger a double free when specific requests are sent to the dcmqrdb program, potentially enabling a Denial of Service (DoS) attack.

The Impact of CVE-2021-41688

This vulnerability allows attackers to exploit the double free memory issue, which can lead to a DoS condition on the affected system.

Technical Details of CVE-2021-41688

Vulnerability Description

The flaw in DCMTK through 3.6.6 arises from improper handling of memory free operations, causing the program to reuse memory addresses that have already been deallocated.

Affected Systems and Versions

Systems: Any system running DCMTK up to version 3.6.6
Versions: DCMTK through 3.6.6

Exploitation Mechanism

Attackers can craft specific requests to the dcmqrdb program, causing a double free of memory, which may lead to a DoS attack.

Mitigation and Prevention

Immediate Steps to Take

Apply patches and updates provided by the vendor
Monitor system logs for any unusual activities

Long-Term Security Practices

Conduct regular security audits and vulnerability assessments
Implement secure coding practices to avoid memory-related vulnerabilities

Patching and Updates

Ensure timely installation of security patches released by DCMTK to address this vulnerability