CVE-2021-40409 in RLC-410W
Summary
by MITRE • 01/28/2022
An OS command injection vulnerability exists in the device network settings functionality of reolink RLC-410W v3.0.0.136_20121102. At [1] or [2], based on DDNS type, the ddns->password variable, that has the value of the password parameter provided through the SetDdns API, is not validated properly. This would lead to an OS command injection.
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Analysis
by VulDB Data Team • 02/02/2022
The vulnerability identified as CVE-2021-40409 represents a critical operating system command injection flaw within the Reolink RLC-410W security camera device firmware version 3.0.0.136_20121102. This vulnerability specifically targets the device's network settings functionality and manifests through improper validation of the ddns->password variable during Dynamic Domain Name System (DDNS) configuration processes. The flaw occurs when the device processes the password parameter provided through the SetDdns API endpoint, creating an exploitable condition that allows remote attackers to execute arbitrary operating system commands on the affected device. The vulnerability's impact is particularly severe given that it affects a network-connected security device that typically operates in sensitive environments where unauthorized access could lead to complete system compromise and potential surveillance breaches.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the device's firmware codebase. When administrators or legitimate users provide DDNS configuration parameters through the SetDdns API, the system fails to properly sanitize or validate the password variable before incorporating it into system commands. This lack of proper input validation creates a classic command injection vector where attacker-controlled input can be interpreted by the operating system as executable commands rather than simple parameter values. The vulnerability specifically manifests at two distinct code locations [1] or [2] depending on the DDNS type configuration, indicating that the flaw exists within the device's DDNS implementation logic where different handling paths for various DDNS types fail to implement consistent input sanitization measures. The absence of proper parameter validation allows malicious payloads to be executed with the privileges of the device's operating system, potentially enabling attackers to gain full control over the camera's functionality.
The operational impact of this vulnerability extends beyond simple unauthorized command execution to encompass complete device compromise and potential network infiltration. An attacker who successfully exploits this vulnerability can execute arbitrary commands on the device, potentially gaining access to sensitive system information, modifying device configurations, or even installing malicious software. The Reolink RLC-410W device, being a network-connected security camera, presents a particularly attractive target for attackers seeking to establish persistent access points within network environments. The vulnerability's exploitation could lead to unauthorized surveillance, data exfiltration, or the device being used as a pivot point for further attacks within the network. Additionally, the device's role in network infrastructure means that compromise could potentially affect other connected devices or systems, creating a broader security impact beyond the individual device itself.
Security mitigations for CVE-2021-40409 should prioritize immediate firmware updates from Reolink to address the input validation deficiencies in the DDNS implementation. Organizations should also implement network segmentation and access controls to limit exposure of these devices to untrusted networks, while monitoring for suspicious API activity or unusual network behavior that might indicate exploitation attempts. Network administrators should consider disabling unnecessary DDNS functionality if it is not required for operations, as this reduces the attack surface. The vulnerability aligns with CWE-77 and CWE-88 categories under the Common Weakness Enumeration framework, specifically addressing improper input validation and command injection flaws. From an ATT&CK framework perspective, this vulnerability maps to techniques involving command execution and privilege escalation, potentially enabling adversaries to establish persistence through the device's network connectivity. The vulnerability also represents a significant concern for organizations implementing zero-trust security models, as it demonstrates how legacy or IoT devices can introduce critical security gaps that undermine overall network security posture.