CVE-2021-31439 : Exploit Details and Defense Strategies

A critical vulnerability in Synology DiskStation Manager allows network-adjacent attackers to execute arbitrary code without requiring authentication. The issue lies in the processing of DSI structures in Netatalk, enabling attackers to execute code within the current process.

Understanding CVE-2021-31439

This section will delve into the details of CVE-2021-31439, including its impact, technical description, affected systems, exploitation mechanism, and mitigation techniques.

What is CVE-2021-31439?

CVE-2021-31439 is a heap-based buffer overflow vulnerability in Synology DiskStation Manager that allows remote attackers to execute arbitrary code on affected systems without needing authentication. The flaw results from inadequate validation of user-supplied data length.

The Impact of CVE-2021-31439

The vulnerability poses a high risk as attackers can exploit it to execute malicious code in the context of the affected process. This could lead to a complete compromise of the system, resulting in confidentiality, integrity, and availability issues.

Technical Details of CVE-2021-31439

This section will provide specific technical details about the vulnerability, including its description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The flaw exists in the processing of DSI structures in Netatalk within Synology DiskStation Manager. Attackers can abuse this issue to execute arbitrary code in the current process.

Affected Systems and Versions

The vulnerability affects Synology DiskStation Manager version 6.1.1-15101-4.

Exploitation Mechanism

Attackers can exploit the lack of proper validation of user-supplied data length to trigger a heap-based buffer overflow, allowing them to execute malicious code.

Mitigation and Prevention

This section will outline immediate steps to take, long-term security practices, and the importance of patching and updates.

Immediate Steps to Take

Users should apply security updates issued by Synology promptly to mitigate the risk of exploitation. Additionally, considering network segmentation and access controls can help reduce the attack surface.

Long-Term Security Practices

Implementing secure coding practices, conducting regular security assessments, and educating users on phishing and social engineering threats are essential for maintaining long-term security.

Patching and Updates

Regularly monitor for security advisories from Synology and apply patches as soon as they are released to protect systems from known vulnerabilities.