CVE-2021-20091 Explained : Impact and Mitigation

A Static Code Injection vulnerability has been discovered in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24. An authenticated remote attacker could exploit this issue to modify device configuration, potentially leading to remote code execution.

Understanding CVE-2021-20091

This CVE involves a security flaw in Buffalo WSR-2533DHPL2 and WSR-2533DHP3 firmware versions that could allow a remote attacker to execute malicious code by manipulating user input.

What is CVE-2021-20091?

The CVE-2021-20091 vulnerability pertains to the lack of proper user input sanitization in the web interfaces of specific Buffalo router firmware versions, opening the door for attackers to alter device configurations.

The Impact of CVE-2021-20091

If successfully exploited, the vulnerability could result in unauthorized remote access to the affected devices and potential execution of arbitrary code, compromising device security and integrity.

Technical Details of CVE-2021-20091

The details below provide insights into the vulnerability, affected systems, and the exploitation mechanism.

Vulnerability Description

The flaw arises from inadequate input validation in Buffalo WSR-2533DHPL2 and WSR-2533DHP3 firmware versions, enabling authenticated remote attackers to manipulate user input to execute unauthorized code.

Affected Systems and Versions

Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 are impacted by this vulnerability.

Exploitation Mechanism

By leveraging the lack of input sanitization, attackers with authenticated access can potentially exploit this vulnerability to gain unauthorized control over affected devices and execute malicious code.

Mitigation and Prevention

To address CVE-2021-20091, immediate steps, security best practices, and the importance of patching are highlighted below.

Immediate Steps to Take

Users are advised to apply firmware updates provided by the vendor to mitigate the risk of exploitation. Additionally, users should enforce strong authentication measures and monitor device activity for suspicious behavior.

Long-Term Security Practices

Implementing network segmentation, restricting access to administrative interfaces, and conducting regular security audits can enhance the overall security posture and help prevent similar vulnerabilities.

Patching and Updates

Regularly check for firmware updates from Buffalo for WSR-2533DHPL2 and WSR-2533DHP3 routers, and promptly apply patches to ensure devices are protected against known security vulnerabilities.