CVE-2021-44383 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. SetAutoUpgrade 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-2021-44383 affects the reolink RLC-410W security camera firmware version 3.0.0.136_20121102, specifically within the cgiserver.cgi component responsible for parsing JSON commands. This denial of service flaw represents a critical security weakness that allows remote attackers to disrupt the device's normal operation through crafted HTTP requests. The vulnerability stems from improper input validation and sanitization within the JSON command parser, creating a pathway for malicious actors to exploit the device's functionality and cause unintended system behavior.
The technical implementation of this vulnerability involves the improper handling of the SetAutoUpgrade parameter within the JSON parsing logic of the cgiserver.cgi script. When an attacker crafts a malicious HTTP request containing a specially formatted JSON payload with the SetAutoUpgrade parameter, the system fails to properly validate the parameter's data type and structure. This parsing error occurs because the system expects the parameter to be an object but receives malformed input that causes the parser to malfunction. The lack of proper input validation and error handling creates a condition where the system cannot gracefully process unexpected data types, leading to a complete system reboot.
The operational impact of this vulnerability extends beyond simple service disruption, as it provides attackers with a mechanism to remotely compromise the device's availability and functionality. The reboot triggered by this vulnerability effectively renders the security camera temporarily inaccessible, which can have significant implications for surveillance operations and network security monitoring. Given that the RLC-410W is designed for security applications, this denial of service condition creates a window of opportunity for attackers to compromise the security posture of the network. The vulnerability affects the device's ability to maintain continuous monitoring capabilities, potentially leaving areas unprotected during the reboot period.
This vulnerability aligns with CWE-20, "Improper Input Validation," which classifies the issue as a fundamental weakness in input handling that can lead to various security consequences including system instability and denial of service conditions. The attack pattern follows the MITRE ATT&CK framework's T1499.004 technique for "Endpoint Termination" and T1566.001 for "Phishing with Malicious Attachment," as the attack requires crafting malicious HTTP requests to exploit the device's web interface. The vulnerability demonstrates poor defensive programming practices and inadequate error handling mechanisms that fail to account for malformed input conditions.
Mitigation strategies should prioritize immediate firmware updates from reolink to address the root cause of the vulnerability, as the manufacturer likely released patches to properly validate the SetAutoUpgrade parameter and implement robust error handling in the JSON parser. Network segmentation and access control measures should be implemented to limit exposure of the device to untrusted networks, while monitoring systems should be deployed to detect anomalous HTTP request patterns that may indicate exploitation attempts. Additionally, administrators should consider disabling unnecessary web services and implementing web application firewalls to filter potentially malicious requests before they reach the vulnerable component. The vulnerability highlights the importance of proper input validation and defensive programming practices in embedded systems, particularly those with network connectivity and security implications.