CVE-2021-41689 : Exploit Details and Defense Strategies

DCMTK through 3.6.6 has a vulnerability that could lead to a DoS attack by mishandling string copy operations.

Understanding CVE-2021-41689

What is CVE-2021-41689?

DCMTK through version 3.6.6 is susceptible to a vulnerability where sending specific requests to the dcmqrdb program can result in a head-based overflow due to improper handling of string copy operations. This flaw could be exploited by an attacker to launch a Denial of Service (DoS) attack.

The Impact of CVE-2021-41689

The vulnerability in DCMTK through 3.6.6 could allow an attacker to exploit the string copy issue and execute a DoS attack, potentially disrupting the availability of the affected system.

Technical Details of CVE-2021-41689

Vulnerability Description

The flaw in DCMTK allows an attacker to trigger a head-based overflow by sending specific requests to the dcmqrdb program, even if the query result is null, due to improper handling of string copy operations.

Affected Systems and Versions

Product: Not Applicable
Vendor: Not Applicable
Versions affected: All versions up to and including 3.6.6

Exploitation Mechanism

The vulnerability can be exploited by sending crafted requests to the dcmqrdb program, leading to a head-based overflow and enabling an attacker to launch a DoS attack.

Mitigation and Prevention

Immediate Steps to Take

Users are advised to update DCMTK to version 3.6.7 or later, which contains a patch to address this vulnerability.
Implement network segmentation to minimize the impact of potential attacks.

Long-Term Security Practices

Regularly monitor and update software to ensure the latest security patches are applied.
Conduct security audits and penetration testing to identify and address vulnerabilities proactively.

Patching and Updates

It is essential to apply the latest patches and updates provided by the software vendor to mitigate the risk of exploitation.