CVE-2021-40415 in RLC-410W
Summary
by MITRE • 01/28/2022
An incorrect default permission vulnerability exists in the cgiserver.cgi cgi_check_ability functionality of reolink RLC-410W v3.0.0.136_20121102. In cgi_check_ability the Format API does not have a specific case, the user permission will default to 7. This will give non-administrative users the possibility to format the SD card and reboot the device.
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Analysis
by VulDB Data Team • 02/02/2022
The vulnerability identified as CVE-2021-40415 represents a critical access control flaw within the Reolink RLC-410W security camera firmware version 3.0.0.136_20121102. This issue resides in the cgiserver.cgi component, specifically within the cgi_check_ability functionality that governs user permissions for various administrative operations. The flaw manifests when the Format API lacks a dedicated permission case, causing the system to default to permission level 7, which grants extensive privileges typically reserved for administrative users. This misconfiguration creates a privilege escalation pathway that allows regular users to execute sensitive operations that should be restricted to authorized administrators only.
The technical implementation of this vulnerability stems from improper permission handling within the camera's web-based management interface. When the cgi_check_ability function processes API requests for the Format functionality, it fails to explicitly validate user permissions for this specific operation. Without a defined permission case for the Format API, the system falls back to a default permission level of 7, which corresponds to full administrative privileges in the camera's permission schema. This default behavior violates the principle of least privilege and creates an unintended access path that bypasses normal authentication mechanisms.
The operational impact of this vulnerability is significant as it enables non-administrative users to perform critical system operations that could compromise the device's integrity and functionality. Specifically, authenticated users can leverage this flaw to format the SD card storage, potentially resulting in complete loss of recorded footage and security data. Additionally, the vulnerability allows unauthorized users to reboot the device remotely, which could disrupt surveillance operations and potentially create denial-of-service conditions. These capabilities represent a serious threat to the security and reliability of the surveillance system, as they provide attackers with means to both destroy evidence and disable monitoring capabilities.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues in software systems. The flaw demonstrates a clear failure in implementing proper authorization checks, allowing privilege escalation through default permission settings. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' tactic. Organizations using Reolink RLC-410W devices should implement immediate mitigations including firmware updates from the vendor, network segmentation to limit access to the device's management interface, and monitoring for unauthorized access attempts. Additionally, administrators should review and restrict user accounts to ensure only authorized personnel have access to critical system functions, as the default permission behavior creates an inherent risk that cannot be easily remediated without proper system updates.