CVE-2021-44377 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. SetImage 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-2021-44377 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 resides within the cgiserver.cgi component's JSON command parser functionality, which serves as the primary interface for device configuration and control operations. The vulnerability specifically manifests when the system processes HTTP requests containing malformed JSON data, particularly in the SetImage parameter handling. The root cause stems from inadequate input validation and improper error handling within the JSON parsing mechanism, creating a scenario where malformed data can cause the device to crash and subsequently reboot.
The technical exploitation of this vulnerability occurs through carefully crafted HTTP requests that manipulate the JSON command parser's expected parameter structure. When an attacker sends an HTTP request containing a malformed SetImage parameter that is not properly formatted as a JSON object, the cgiserver.cgi component fails to handle this unexpected input gracefully. Instead of returning an appropriate error response or rejecting the malformed request, the system experiences a critical failure that results in an automatic device reboot. This behavior constitutes a classic buffer overflow or parsing error condition that falls under CWE-121, which describes heap-based buffer overflow conditions. The vulnerability demonstrates poor input validation practices and lacks proper exception handling mechanisms that would normally protect against malformed data processing.
From an operational impact perspective, this vulnerability creates significant security concerns for organizations relying on reolink RLC-410W devices for surveillance operations. The denial of service condition can be exploited remotely without authentication requirements, allowing attackers to repeatedly reboot the device and potentially disrupt critical security monitoring operations. This disruption can occur at any time, as the vulnerability is triggered by simply sending an HTTP request to the device's web interface. The device reboot process can lead to gaps in security monitoring, potential data loss, and operational downtime that may go unnoticed for extended periods. According to ATT&CK framework domain T1499, this vulnerability maps to the "Endpoint Denial of Service" technique, where adversaries compromise endpoint systems to prevent normal operations.
The mitigation strategies for CVE-2021-44377 should prioritize immediate firmware updates from reolink to address the underlying JSON parsing flaw. Network segmentation and access control measures can help limit exposure by restricting direct internet access to these devices and implementing proper firewall rules that filter malformed HTTP requests. Organizations should also consider implementing intrusion detection systems that can identify suspicious HTTP traffic patterns targeting the cgiserver.cgi endpoint. Additionally, regular security assessments of networked devices and maintaining up-to-date vulnerability management processes are essential for preventing exploitation of similar parsing vulnerabilities. The vulnerability highlights the importance of proper input validation and error handling in embedded web services, emphasizing that all user-supplied data must be rigorously validated before processing to prevent system instability and maintain operational continuity.