CVE-2021-44416 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. Disconnect 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 identified as CVE-2021-44416 represents a critical denial of service weakness within the cgiserver.cgi component of Reolink RLC-410W security cameras running firmware version v3.0.0.136_20121102. This issue resides in the JSON command parser functionality that processes HTTP requests sent to the device's web interface. The vulnerability stems from inadequate input validation and improper error handling within the camera's web server implementation, specifically when processing the disconnect parameter in JSON formatted requests. The flaw manifests when the system encounters a malformed HTTP request containing a disconnect parameter that is not properly structured as a JSON object, leading to unexpected behavior that ultimately results in system reboot.
The technical exploitation of this vulnerability occurs through the manipulation of HTTP requests sent to the affected Reolink device. When an attacker crafts a malicious request with a malformed disconnect parameter that violates the expected JSON object structure, the cgiserver.cgi component fails to properly parse this input. This parsing failure triggers a cascade of system errors that culminates in an automatic reboot of the device. The vulnerability is classified as a CWE-20: Improper Input Validation, which is a fundamental weakness in software design where input data is not properly validated before processing. The lack of proper parameter validation and error handling creates a condition where malformed input can cause system instability and denial of service.
From an operational standpoint, this vulnerability poses significant risks to security camera deployments where continuous monitoring is critical. The remote reboot capability allows attackers to disrupt surveillance operations without requiring physical access to the device, potentially creating windows of opportunity for additional attacks. The attack vector is particularly concerning as it requires only network access to execute, making it accessible to remote threat actors. The vulnerability can be exploited repeatedly, potentially leading to persistent service disruption that could compromise security operations. 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.
The mitigation strategy for this vulnerability requires immediate firmware updates from Reolink to address the parsing error in the cgiserver.cgi component. Network administrators should implement access controls to limit HTTP request access to authorized personnel only and consider network segmentation to restrict access to security camera devices. Monitoring for unusual reboot patterns and unauthorized HTTP requests should be enabled to detect potential exploitation attempts. Additionally, implementing network-based intrusion detection systems can help identify and block malicious requests targeting this specific vulnerability. Organizations should also consider disabling unnecessary web services when possible and maintain detailed logs of all HTTP requests to the affected devices for forensic analysis purposes. The vulnerability highlights the importance of robust input validation and proper error handling in embedded systems, particularly in security devices where reliability and continuous operation are paramount requirements.