CVE-2022-37076 in A7000R
Summary
by MITRE • 08/25/2022
TOTOLINK A7000R V9.1.0u.6115_B20201022 was discovered to contain a command injection vulnerability via the FileName parameter in the function UploadFirmwareFile.
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Analysis
by VulDB Data Team • 10/01/2022
The vulnerability identified as CVE-2022-37076 represents a critical command injection flaw within the TOTOLINK A7000R router firmware version V9.1.0u.6115_B20201022. This issue resides in the UploadFirmwareFile function where the FileName parameter is improperly handled, creating an avenue for malicious actors to execute arbitrary commands on the affected device. The vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly filter user-supplied data before incorporating it into system commands. This type of vulnerability falls under the Common Weakness Enumeration category CWE-77 which specifically addresses command injection flaws where untrusted data is concatenated or interpolated into shell commands without proper escaping or sanitization.
The operational impact of this vulnerability is severe as it allows remote attackers to gain unauthorized access to the router's underlying operating system. An attacker could potentially execute system commands with elevated privileges, leading to complete compromise of the device. This includes the ability to modify firmware, access network traffic, redirect connections, or establish persistent backdoors. The vulnerability is particularly concerning because it affects a widely deployed consumer-grade router model, making it a prime target for automated exploitation campaigns. The attack surface is expanded by the fact that the vulnerability exists in the firmware upload functionality, which is a legitimate administrative feature that must remain accessible for legitimate users while also being protected from malicious use.
The security implications extend beyond simple command execution as this vulnerability enables attackers to perform privilege escalation and maintain persistent access to the network infrastructure. The affected TOTOLINK A7000R router serves as a gateway for network traffic, making successful exploitation a significant threat to overall network security. Attackers could leverage this vulnerability to perform man-in-the-middle attacks, monitor network communications, or use the compromised device as a pivot point for attacking other systems within the local network. The vulnerability's classification aligns with ATT&CK technique T1059.001 which covers command and scripting interpreter, specifically shell scripting and command execution. Network defenders must consider this vulnerability as part of their broader threat landscape, particularly in environments where such devices are deployed without proper network segmentation or monitoring.
Mitigation strategies should focus on immediate firmware updates from TOTOLINK to address the command injection flaw in the UploadFirmwareFile function. Organizations should implement network monitoring to detect anomalous behavior that might indicate exploitation attempts, including unusual traffic patterns or unexpected command executions. Network segmentation and access controls should be enforced to limit the potential damage from compromised devices. The vulnerability demonstrates the importance of secure coding practices in embedded systems, particularly regarding input validation and command construction. Regular security assessments of network infrastructure and firmware inventory management should be implemented to identify and remediate similar vulnerabilities across the enterprise. Additionally, network administrators should consider disabling unnecessary administrative functions and implementing strict access controls to reduce the attack surface available to potential attackers.