CVE-2021-40414

An incorrect default permission vulnerability exists in the cgiserver.cgi cgi_check_ability functionality of reolink RLC-410W v3.0.0.136_20121102. The SetMdAlarm API sets the movement detection parameters, giving the ability to set the sensitivity of the camera per a range of hours, and which of the camera spaces to ignore when considering movement detection. Because in cgi_check_ability the SetMdAlarm API does not have a specific case, the user permission will default to 7. This will give non-administrative users the possibility to change the movement detection parameters.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1425