CVE-2021-27649 : Exploit Details and Defense Strategies

A critical 'use after free' vulnerability has been discovered in the file transfer protocol component of Synology DiskStation Manager (DSM) before version 6.2.3-25426-3. This vulnerability could allow remote attackers to execute arbitrary code, posing a severe risk to the security of affected systems.

Understanding CVE-2021-27649

This section delves into the specifics of CVE-2021-27649, shedding light on its impact and technical details.

What is CVE-2021-27649?

CVE-2021-27649 is a 'use after free' vulnerability present in Synology DiskStation Manager (DSM) versions prior to 6.2.3-25426-3. It enables malicious actors to exploit the file transfer protocol component, leading to the execution of arbitrary code remotely.

The Impact of CVE-2021-27649

With a CVSSv3 base score of 9.8 out of 10, CVE-2021-27649 carries a critical severity rating. The vulnerability's high impact on confidentiality, integrity, and availability makes it a significant security concern for affected systems.

Technical Details of CVE-2021-27649

This section explores the vulnerability description, affected systems, and the exploitation mechanism in detail.

Vulnerability Description

The vulnerability arises from a 'use after free' flaw in the file transfer protocol component of Synology DiskStation Manager (DSM) versions preceding 6.2.3-25426-3. This flaw is exploited by remote attackers to execute arbitrary code on vulnerable systems.

Affected Systems and Versions

The issue impacts Synology DiskStation Manager (DSM) installations that are running versions earlier than 6.2.3-25426-3. Organizations using these versions are at risk of exploitation and compromise.

Exploitation Mechanism

Remote attackers leverage unspecified vectors to trigger the 'use after free' vulnerability in the file transfer protocol component of vulnerable DSM installations. By exploiting this flaw, threat actors can execute malicious code on the target system.

Mitigation and Prevention

In response to CVE-2021-27649, it is crucial to take immediate steps to secure your systems and implement long-term security measures.

Immediate Steps to Take

Update Synology DiskStation Manager (DSM) to version 6.2.3-25426-3 or later to mitigate the vulnerability.
Monitor network traffic for any signs of suspicious activity or exploitation attempts.
Consider implementing network segmentation and access controls to limit the attack surface.

Long-Term Security Practices

Regularly patch and update all software and firmware to address known security issues.
Conduct security training for employees to educate them on identifying and reporting potential security threats.

Patching and Updates

Synology has released updates to address CVE-2021-27649. It is recommended to install these patches promptly to eliminate the risk posed by the vulnerability.