CVE-2019-9949 : Exploit Details and Defense Strategies

A vulnerability allowing code execution has been found in various Western Digital My Cloud models, enabling attackers to gain root access by exploiting a specific file.

Understanding CVE-2019-9949

This CVE identifies a critical security flaw in multiple Western Digital My Cloud models that could lead to unauthorized code execution.

What is CVE-2019-9949?

The vulnerability in Western Digital My Cloud models allows attackers to escalate privileges and execute arbitrary code by abusing symbolic links.

The Impact of CVE-2019-9949

The vulnerability permits attackers to gain root access, starting from a low-privilege user session, potentially leading to unauthorized system control and data manipulation.

Technical Details of CVE-2019-9949

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability arises from inadequate sanitization of the "name" parameter in the cgi_unzip command, enabling attackers to execute arbitrary code.

Affected Systems and Versions

Western Digital My Cloud Cloud
Mirror Gen2
EX2 Ultra
EX2100
EX4100
DL2100
DL4100
PR2100
PR4100
Versions prior to firmware 2.31.183

Exploitation Mechanism

Attackers exploit the cgi-bin/webfile_mgr.cgi file by uploading a tar archive containing a symbolic link and another archive that writes a file to the linked location using the "cgi_untar" command.
The vulnerability allows for arbitrary file write actions, potentially compromising system integrity.

Mitigation and Prevention

Protecting systems from CVE-2019-9949 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update affected Western Digital My Cloud models to firmware version 2.31.183 or later.
Monitor system logs for any suspicious activities or unauthorized access attempts.
Implement network segmentation to limit the impact of potential breaches.

Long-Term Security Practices

Regularly update firmware and security patches to mitigate future vulnerabilities.
Conduct security audits and penetration testing to identify and address potential weaknesses.

Patching and Updates

Western Digital has released firmware version 2.31.183 to address the vulnerability.
Ensure timely installation of security updates and patches to safeguard systems against known exploits.