CVE-2020-14993 : Security Advisory and Response

A stack-based buffer overflow vulnerability on DrayTek Vigor2960, Vigor3900, and Vigor300B devices before 1.5.1.1 allows remote attackers to execute arbitrary code.

Understanding CVE-2020-14993

This CVE involves a critical security issue in DrayTek networking devices that could lead to remote code execution.

What is CVE-2020-14993?

This CVE identifies a stack-based buffer overflow vulnerability present in specific DrayTek devices, enabling malicious actors to run arbitrary code by exploiting a particular parameter.

The Impact of CVE-2020-14993

The vulnerability poses a severe risk as attackers can execute unauthorized code on affected devices, potentially leading to complete system compromise.

Technical Details of CVE-2020-14993

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The flaw exists in DrayTek Vigor2960, Vigor3900, and Vigor300B devices before version 1.5.1.1, allowing attackers to trigger a stack-based buffer overflow via the formuserphonenumber parameter in an authusersms action to mainfunction.cgi.

Affected Systems and Versions

DrayTek Vigor2960, Vigor3900, and Vigor300B devices before version 1.5.1.1

Exploitation Mechanism

The vulnerability can be exploited remotely by sending a crafted request containing malicious data to the specific parameter mentioned above.

Mitigation and Prevention

Protecting systems from CVE-2020-14993 requires immediate action and long-term security measures.

Immediate Steps to Take

Update affected DrayTek devices to version 1.5.1.1 or later to mitigate the vulnerability.
Monitor network traffic for any suspicious activity that could indicate exploitation attempts.

Long-Term Security Practices

Regularly update firmware and security patches on all network devices to prevent future vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential security breaches.

Patching and Updates

DrayTek has released version 1.5.1.1 to address the vulnerability. Ensure all affected devices are promptly updated to this version to eliminate the risk of exploitation.