CVE-2022-25076 in A800R
Summary
by MITRE • 02/24/2022
TOTOLink A800R V4.1.2cu.5137_B20200730 was discovered to contain a command injection vulnerability in the "Main" function. This vulnerability allows attackers to execute arbitrary commands via the QUERY_STRING parameter.
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Analysis
by VulDB Data Team • 02/26/2022
The vulnerability identified as CVE-2022-25076 affects the TOTOLink A800R router model running firmware version V4.1.2cu.5137_B20200730. This represents a critical security flaw that stems from improper input validation within the device's web interface handling mechanism. The vulnerability exists within the "Main" function of the router's embedded web server implementation, where user-supplied data from the QUERY_STRING parameter is not adequately sanitized or validated before being processed.
The technical nature of this vulnerability aligns with CWE-77, which describes command injection flaws occurring when untrusted data is passed to system commands. In this case, the router's web interface fails to properly escape or validate the QUERY_STRING parameter, allowing an attacker to inject malicious commands that get executed within the context of the router's operating system. This type of vulnerability is particularly dangerous because it provides attackers with direct access to the underlying system shell, potentially enabling full administrative control over the device.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it creates a persistent backdoor that attackers can exploit to maintain long-term control over the affected router. Once exploited, the attacker can execute arbitrary code with the privileges of the web server process, which typically runs with elevated permissions on the device. This enables a wide range of malicious activities including network monitoring, data exfiltration, redirection of traffic, or even using the compromised device as a pivot point for attacking other systems within the local network. The vulnerability is particularly concerning because it affects a consumer-grade router that may be deployed in residential or small office environments where security monitoring is minimal.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1059.001 for command and scripting interpreter and T1071.004 for application layer protocol. The attack surface is broad as the vulnerability is accessible via HTTP requests to the router's web interface, making it exploitable from both internal and external network positions. Mitigation strategies should include immediate firmware updates from the vendor, network segmentation to limit access to the router's web interface, and implementing network monitoring to detect suspicious HTTP traffic patterns. Additionally, organizations should consider disabling unnecessary web management interfaces and implementing proper access controls to reduce the attack surface. The vulnerability underscores the importance of secure coding practices and input validation in embedded systems, particularly those handling network traffic and user interactions.