CVE-2021-44368 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. SetNetPort 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 vulnerability CVE-2021-44368 represents a critical denial of service condition affecting the reolink RLC-410W security camera device running firmware version 3.0.0.136_20121102. This issue resides within the cgiserver.cgi component which processes JSON commands through the HTTP interface, specifically targeting the SetNetPort parameter handling mechanism. The flaw manifests when the system receives a malformed HTTP request containing a JSON payload where the SetNetPort parameter is not properly structured as an object, causing the device to crash and subsequently reboot. This type of vulnerability falls under CWE-20, known as Improper Input Validation, where the system fails to properly validate the structure and content of incoming data before processing it. The attack vector is particularly concerning as it requires only a simple HTTP request to be sent to the device's web interface, making it accessible to remote attackers without requiring physical access or authentication credentials.
The technical implementation of this vulnerability demonstrates a classic buffer overflow and improper parameter handling scenario where the JSON parser does not adequately validate the expected data structure for the SetNetPort parameter. When the cgiserver.cgi component attempts to process the malformed JSON input, it fails to properly validate that the parameter is indeed an object as expected by the parser logic. This validation failure leads to an unhandled exception within the device's processing pipeline, causing the system to crash and automatically reboot. The vulnerability is particularly dangerous because it operates at the application layer of the network stack, targeting the web server component that handles all HTTP communications with the device. According to ATT&CK framework, this represents a T1499.004 technique involving network denial of service attacks, where the attacker leverages a software vulnerability to disrupt legitimate service availability. The device's reboot behavior creates a persistent denial of service condition that can be repeatedly triggered, effectively rendering the security camera inoperative until manual intervention or power cycle occurs.
The operational impact of CVE-2021-44368 extends beyond simple service disruption to create significant security implications for networked surveillance infrastructure. Organizations relying on reolink RLC-410W cameras for security monitoring face potential exposure during active attacks, as the device becomes temporarily unavailable for video recording, motion detection, or remote access capabilities. The vulnerability affects the camera's network configuration functionality, meaning attackers could potentially disrupt network connectivity or access controls, though the immediate impact is limited to device rebooting rather than privilege escalation or data compromise. The lack of authentication requirements for triggering this vulnerability means that any remote attacker with network access to the device can exploit it, making it particularly dangerous in environments where security cameras are exposed to untrusted networks or internet-facing configurations. This vulnerability represents a significant concern for industrial control systems and IoT security, as it demonstrates how seemingly minor input validation flaws can create substantial availability issues in security-critical devices.
Mitigation strategies for CVE-2021-44368 should focus on immediate firmware updates from reolink to address the root cause of the JSON parsing vulnerability. Organizations should implement network segmentation to isolate security cameras from general network traffic, reducing exposure to potential attackers. Network monitoring solutions should be configured to detect unusual reboot patterns or repeated HTTP requests to camera web interfaces, which could indicate exploitation attempts. Additionally, implementing firewall rules to restrict access to the camera's web interface to trusted IP addresses only can provide an additional layer of protection. The vulnerability highlights the importance of proper input validation in embedded systems and web applications, emphasizing that even simple parameter handling can create critical security weaknesses. Security teams should also consider implementing intrusion detection systems specifically configured to monitor for patterns consistent with this type of denial of service attack, particularly focusing on JSON parsing anomalies and HTTP request structures that might trigger similar vulnerabilities in other networked devices. Regular vulnerability assessments of networked security infrastructure are essential to identify and remediate similar weaknesses before they can be exploited by malicious actors.