CVE-2021-27506 Explained : Impact and Mitigation

This article provides detailed information about CVE-2021-27506, a vulnerability in the ClamAV Engine component embedded in Storsmshield Network Security (SNS) software.

Understanding CVE-2021-27506

This section delves into the impact, technical details, and mitigation strategies related to CVE-2021-27506.

What is CVE-2021-27506?

The ClamAV Engine, specifically versions 0.103.1 and below, integrated into Storsmshield Network Security (SNS) is susceptible to a Denial of Service (DoS) vulnerability triggered by parsing malformed PNG files. This vulnerability affects Netasq versions 9.1.0 to 9.1.11 and SNS versions 1.0.0 to 4.2.0, with fixes implemented in SNS versions 3.7.19, 3.11.7, and 4.2.1.

The Impact of CVE-2021-27506

The vulnerability allows attackers to exploit the processing of malformed PNG files, leading to potential DoS conditions in the affected software versions.

Technical Details of CVE-2021-27506

This section outlines the specific technical aspects of the CVE, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability in the ClamAV Engine within SNS enables a malicious actor to trigger a DoS condition through the processing of specially crafted PNG files, impacting the network security functionality.

Affected Systems and Versions

The vulnerability affects Netasq versions 9.1.0 to 9.1.11 and SNS versions 1.0.0 to 4.2.0, highlighting the importance of updating to the patched versions for enhanced security.

Exploitation Mechanism

Attackers can exploit this vulnerability by providing malicious PNG files to the affected ClamAV Engine, causing it to parse the files incorrectly and resulting in a denial of service scenario.

Mitigation and Prevention

Explore the following key strategies to mitigate the risks associated with CVE-2021-27506 and safeguard your systems.

Immediate Steps to Take

Update SNS to versions 3.7.19, 3.11.7, or 4.2.1 to patch the vulnerability and prevent exploitation.
Implement network segmentation to restrict access to vulnerable components and minimize the attack surface.

Long-Term Security Practices

Regularly monitor security advisories and promptly apply patches to address known vulnerabilities.
Conduct security awareness training to educate users on identifying and reporting suspicious activities that may indicate an attack.

Patching and Updates

Stay vigilant about security updates released by Storsmshield and ClamAV to ensure your systems are protected against emerging threats.