CVE-2021-44411 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. Search 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
The CVE-2021-44411 vulnerability represents a critical denial of service flaw within the Reolink RLC-410W security camera firmware version 3.0.0.136_20121102. This vulnerability specifically targets the cgiserver.cgi JSON command parser functionality, which serves as the primary interface for remote management and configuration of the device. The flaw manifests when the system processes HTTP requests containing malformed JSON data, particularly in the search parameter handling mechanism. This vulnerability falls under the CWE-400 category of Uncontrolled Resource Consumption, as the improper input validation leads to resource exhaustion through unintended system reboot cycles. The attack vector is particularly concerning as it requires only a simple HTTP request to be sent to the device, making it highly accessible to potential attackers.
The technical implementation of this vulnerability stems from insufficient input validation within the JSON parser component of the camera's web server. When a maliciously crafted HTTP request is received, the cgiserver.cgi component fails to properly validate the search parameter, which should be a structured JSON object but is instead being processed as an improper data type. This parsing error triggers an unexpected behavior in the system's resource management, ultimately causing the device to reboot automatically. The vulnerability demonstrates a classic example of improper input sanitization where the system does not adequately check the data type and structure of incoming JSON parameters before processing them. According to ATT&CK framework, this represents a privilege escalation and denial of service technique under the T1499.004 sub-technique for Network Denial of Service, as the attacker can disrupt service availability without requiring elevated privileges.
The operational impact of this vulnerability extends beyond simple device unavailability, as it creates potential for extended service disruption in security monitoring environments where these cameras serve as critical components. The automatic reboot cycle can occur repeatedly, potentially leading to complete system unavailability for extended periods, which undermines the security posture of the monitored environment. In enterprise or industrial settings, such a vulnerability could result in significant operational downtime and compromise security coverage during critical periods. The vulnerability also poses risks for attackers seeking to exploit the device for further penetration attempts, as the repeated reboots can obscure other attack patterns or facilitate the installation of persistent backdoors. Organizations relying on Reolink RLC-410W devices for security monitoring must consider the potential for cascading failures if multiple devices in a network are affected by similar vulnerabilities, as this could lead to complete loss of surveillance coverage in critical areas.
Mitigation strategies for CVE-2021-44411 should prioritize immediate firmware updates from Reolink, as the vendor has likely released patches addressing this specific parsing error. Network segmentation and access control measures should be implemented to restrict HTTP access to these devices, limiting the attack surface available to potential adversaries. Implementing intrusion detection systems capable of identifying malformed JSON requests can provide early warning of exploitation attempts. Additionally, organizations should consider disabling unnecessary web management interfaces and implementing monitoring for unexpected device reboots or restart patterns. The vulnerability highlights the importance of input validation and proper error handling in embedded systems, particularly those handling JSON data in security-critical applications. Security teams should also conduct comprehensive vulnerability assessments of their entire network infrastructure to identify similar parsing vulnerabilities in other devices that may be running outdated firmware versions or lack proper input validation mechanisms.