CVE-2021-44412 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. GetRec 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-2021-44412 vulnerability represents a critical denial of service condition affecting the reolink RLC-410W security camera device running firmware version v3.0.0.136_20121102. This flaw manifests within the cgiserver.cgi component's JSON command parser functionality, which serves as the primary interface for device configuration and control operations. The vulnerability stems from insufficient input validation and improper error handling mechanisms within the JSON parsing routine that processes HTTP requests sent to the device's web interface. The specific technical weakness lies in the parser's inability to properly handle malformed JSON data structures, particularly when processing the GetRec parameter, which is expected to be a JSON object but can be manipulated to trigger unexpected behavior. This represents a classic example of improper input validation that aligns with CWE-20, which catalogs weaknesses related to improper input validation in software systems. The vulnerability operates at the application layer of the network stack, making it particularly dangerous as it can be exploited remotely without requiring physical access to the device or specialized authentication credentials.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable broader attack vectors within networked environments. When an attacker crafts a specially-crafted HTTP request containing malformed JSON data, the device's JSON parser fails to properly validate the incoming data structure, leading to a complete system reboot. This reboot condition effectively renders the security camera non-functional for the duration of the device's restart cycle, which can last several minutes depending on the device's configuration and hardware specifications. The attack surface is particularly concerning given that security cameras are often deployed in critical infrastructure environments where continuous monitoring is essential for security operations. The vulnerability's exploitation requires minimal technical expertise, as it only necessitates sending a specific HTTP request to the device's web interface, making it accessible to attackers with basic network reconnaissance capabilities. This aligns with ATT&CK technique T1499.001, which covers network denial of service attacks targeting network infrastructure components.
Mitigation strategies for CVE-2021-44412 should prioritize immediate firmware updates from reolink as the primary defense mechanism, as the vendor has likely released patches addressing the specific JSON parsing vulnerability. Network administrators should implement firewall rules and access control lists that restrict direct internet access to the device's web interface, limiting exposure to external attackers. Additionally, network segmentation strategies should isolate security camera networks from critical business systems, reducing potential impact if exploitation occurs. The implementation of intrusion detection systems capable of identifying malformed HTTP requests targeting JSON parsing endpoints can provide early warning capabilities. Security monitoring should include regular checks for unauthorized device reboots and unusual network traffic patterns that might indicate exploitation attempts. Organizations should also consider implementing network access control measures that require authentication for all web interface access, even for internal network users. The vulnerability demonstrates the importance of input validation in embedded systems and highlights how seemingly minor parsing flaws can result in complete system compromise through denial of service attacks. Regular security assessments of networked devices, particularly those with web interfaces, should include testing for similar input validation weaknesses to prevent exploitation of similar vulnerabilities.