CVE-2021-44386 in RLC-410W
Summary
by MITRE • 01/29/2022
A denial of service vulnerability exists in the cgiserver.cgi JSON command parser functionality of reolink RLC-410W v3.0.0.136_20121102. A specially-crafted HTTP request can lead to a reboot. SetPtzPatrol param is not object. An attacker can send an HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 02/02/2022
This vulnerability resides within the cgiserver.cgi component of reolink RLC-410W security camera firmware version 3.0.0.136_20121102, specifically targeting the JSON command parser functionality that handles PTZ (Pan-Tilt-Zoom) patrol commands. The flaw manifests when the system processes HTTP requests containing the SetPtzPatrol parameter, which expects a structured JSON object but receives malformed input that disrupts normal parsing operations. This represents a classic buffer over-read and improper input validation issue that falls under CWE-121 as an improper restriction of operations within a recognized black list. The vulnerability operates through a denial of service attack vector where an attacker can craft a specific HTTP request containing malformed JSON data for the SetPtzPatrol parameter, causing the device to crash and subsequently reboot. This type of vulnerability maps directly to the ATT&CK technique T1499.004 for network denial of service attacks, as it leverages a weakness in network service availability. The attack requires minimal privileges and can be executed remotely over HTTP, making it particularly dangerous for security camera deployments where continuous operation is critical for surveillance purposes.
The technical implementation of this vulnerability stems from insufficient input validation within the JSON parser component of the camera's web server. When the cgiserver.cgi script processes an HTTP request containing the SetPtzPatrol parameter, it fails to properly validate that the parameter value conforms to expected JSON object structure. Instead of gracefully handling malformed input or rejecting invalid requests, the parser attempts to process the malformed data and encounters a critical parsing error that leads to system instability. This behavior constitutes a failure in proper error handling and input sanitization, aligning with CWE-252 which addresses improper handling of exceptional conditions. The specific trigger involves sending an HTTP request that includes a SetPtzPatrol parameter that is not properly formatted as a JSON object, causing the system to attempt memory operations that result in a system crash and automatic reboot. The vulnerability demonstrates a lack of robust defensive programming practices and highlights the importance of implementing proper input validation and error recovery mechanisms in embedded network services.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the integrity of security monitoring operations. Security camera systems like the reolink RLC-410W are often deployed in critical infrastructure environments where continuous surveillance is essential for security operations. When an attacker can remotely trigger a device reboot through a simple HTTP request, they effectively create a persistent availability threat that can be exploited to deny security services. This vulnerability directly impacts the CIA triad by compromising availability, potentially allowing attackers to disrupt security operations during critical periods. The attack surface is particularly concerning because it requires no authentication and can be executed over the network, making it an attractive target for adversaries seeking to disable security infrastructure. Organizations relying on these devices for surveillance may experience gaps in monitoring coverage during reboot cycles, potentially allowing unauthorized access or security breaches to occur undetected. The vulnerability also represents a significant risk for industrial control systems and critical infrastructure where security camera systems are part of broader monitoring and security architectures.
Mitigation strategies for this vulnerability should focus on both immediate defensive measures and long-term architectural improvements. The most effective immediate solution involves applying firmware updates from reolink that address the JSON parsing flaw and implement proper input validation for the SetPtzPatrol parameter. Network segmentation and access control measures should be implemented to restrict HTTP access to these devices to authorized personnel only, reducing the attack surface available to potential adversaries. Implementing intrusion detection systems that monitor for unusual HTTP request patterns targeting the cgiserver.cgi component can help detect exploitation attempts. Additionally, organizations should establish regular firmware update procedures and maintain inventory of all networked security devices to ensure timely patch deployment. The vulnerability highlights the importance of implementing proper input validation and error handling in embedded systems, particularly those handling JSON data structures, and aligns with security best practices outlined in NIST SP 800-160 for secure software development lifecycle processes. Organizations should also consider implementing network access controls and monitoring solutions that can detect and prevent exploitation attempts targeting known vulnerabilities in security camera systems.