CVE-2021-40408 : Security Advisory and Response

An OS command injection vulnerability exists in the device network settings functionality of reolink RLC-410W v3.0.0.136_20121102, allowing a remote attacker to execute arbitrary commands on the device.

Understanding CVE-2021-40408

This CVE involves a critical OS command injection vulnerability in Reolink RLC-410W devices.

What is CVE-2021-40408?

The vulnerability arises from improper validation of user input in the device's network settings, potentially leading to unauthorized command execution.

The Impact of CVE-2021-40408

The CVSS v3.0 base score of 9.1 indicates a critical impact with high confidentiality, integrity, and availability impacts. Attackers can exploit this remotely without user interaction.

Technical Details of CVE-2021-40408

The technical specifics of the vulnerability.

Vulnerability Description

The flaw allows an attacker to inject OS commands through the ddns->username variable, derived from the userName parameter of the SetDdns API.

Affected Systems and Versions

Vendor: Reolink
Product: RLC-410W
Versions: v3.0.0.136_20121102 and prior

Exploitation Mechanism

The vulnerability is exploited by not properly validating the ddns->username variable, enabling malicious OS command injection.

Mitigation and Prevention

Actions to secure systems against CVE-2021-40408.

Immediate Steps to Take

Disable remote access if not required
Implement strong firewall rules
Monitor network traffic for suspicious activities

Long-Term Security Practices

Regularly update device firmware
Conduct security assessments and penetration testing
Educate users on secure configuration practices

Patching and Updates

Apply the latest firmware updates from Reolink to address the vulnerability