CVE-2021-44389 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. GetAbility 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
This vulnerability resides in the cgiserver.cgi component of reolink RLC-410W firmware version 3.0.0.136_20121102, representing a critical denial of service flaw that can be exploited to remotely reboot the device. The vulnerability specifically affects the JSON command parser functionality within the web server interface, where improper input validation leads to system instability. The flaw manifests when an attacker crafts a malicious HTTP request containing a GetAbility parameter that does not conform to expected object structure, triggering an unexpected system behavior that results in automatic device reboot. This represents a classic example of improper input validation that can be categorized under CWE-20, which addresses "Improper Input Validation" in software systems. The vulnerability demonstrates a clear path to privilege escalation and system compromise through simple network-based attacks, making it particularly dangerous in security contexts where continuous operation is critical. The attack vector requires only basic network connectivity and does not require authentication, making it accessible to any remote attacker with network access to the device.
The technical implementation of this vulnerability exploits the JSON parsing logic within the cgi server component where the system fails to properly validate the structure of the GetAbility parameter. When an HTTP request is received with malformed JSON data in the GetAbility field, the parser encounters an unexpected data type that causes the system to crash and subsequently reboot. This behavior aligns with ATT&CK technique T1499.004, which covers "OS Command and Control" through device reboot or crash mechanisms. The firmware's lack of proper error handling for malformed JSON input creates an execution path where invalid data triggers system-level failures rather than graceful error recovery. The vulnerability demonstrates a fundamental weakness in the input sanitization process, where the system does not properly distinguish between valid and invalid JSON structures, leading to a complete system restart instead of returning an appropriate error response.
The operational impact of this vulnerability extends beyond simple denial of service, as it can be leveraged to create persistent disruptions in surveillance systems where the RLC-410W cameras are deployed. Network administrators and security personnel face significant challenges when dealing with devices that can be remotely rebooted without authentication, potentially creating gaps in security monitoring or disrupting critical surveillance operations. This vulnerability particularly affects environments where continuous monitoring is essential, such as industrial facilities, retail stores, or security installations where device uptime is paramount. The remote nature of the attack means that even devices protected by firewalls or network segmentation could be compromised if they are accessible over the internet. The vulnerability also represents a potential stepping stone for more sophisticated attacks, as the device reboot may provide an opportunity for attackers to gain further system access or deploy additional malicious payloads.
Mitigation strategies for this vulnerability should include immediate firmware updates from the vendor to address the JSON parsing flaw and implement network segmentation to limit access to the device to trusted networks only. Organizations should also deploy intrusion detection systems that can monitor for suspicious HTTP requests containing malformed JSON data in the GetAbility parameter. Network administrators should consider implementing access control lists that restrict HTTP access to the device to specific IP addresses or ranges. Additionally, the implementation of network-based security controls such as web application firewalls can help detect and block malicious requests before they reach the vulnerable component. The vulnerability highlights the importance of proper input validation and error handling in embedded systems, particularly those handling network-based commands and control functions. Security teams should also implement regular vulnerability assessments and penetration testing to identify similar flaws in other networked devices within their infrastructure, as this represents a common pattern in embedded systems where security is often an afterthought rather than a fundamental design principle.