CVE-2020-5756 Explained : Impact and Mitigation

Grandstream GWN7000 firmware version 1.0.9.4 and below allows authenticated remote users to modify the system's crontab via an undocumented API, enabling attackers to execute arbitrary OS commands on the router.

Understanding CVE-2020-5756

This CVE involves a vulnerability in the Grandstream GWN7000 firmware that permits authenticated remote users to manipulate the system's crontab through an undocumented API, potentially leading to the execution of unauthorized OS commands.

What is CVE-2020-5756?

The CVE-2020-5756 vulnerability in Grandstream GWN7000 firmware versions 1.0.9.4 and below allows authenticated remote users to modify the system's crontab via an undocumented API. This security flaw enables malicious actors to execute arbitrary OS commands on the affected router.

The Impact of CVE-2020-5756

The exploitation of this vulnerability could result in unauthorized access to the router, allowing attackers to execute malicious commands, disrupt network operations, or gain further access to sensitive information.

Technical Details of CVE-2020-5756

This section provides more in-depth technical insights into the CVE-2020-5756 vulnerability.

Vulnerability Description

The vulnerability in Grandstream GWN7000 firmware versions 1.0.9.4 and below allows authenticated remote users to modify the system's crontab through an undocumented API, potentially leading to the execution of arbitrary OS commands.

Affected Systems and Versions

Product: Grandstream GWN7000
Vendor: Tenable
Versions Affected: Versions 1.0.9.4 and below

Exploitation Mechanism

The vulnerability can be exploited by authenticated remote users to manipulate the system's crontab via an undocumented API, providing an avenue for executing unauthorized OS commands.

Mitigation and Prevention

Protecting systems from CVE-2020-5756 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update the Grandstream GWN7000 firmware to a version that addresses the vulnerability.
Monitor network traffic for any suspicious activities that might indicate exploitation attempts.

Long-Term Security Practices

Implement strong authentication mechanisms to prevent unauthorized access to the router.
Regularly review and update access control policies to enhance security posture.

Patching and Updates

Stay informed about security advisories from Grandstream and Tenable regarding patches for CVE-2020-5756.
Promptly apply recommended patches and updates to mitigate the risk of exploitation.