CVE-2021-45876 in GARO Wallbox GLB
Summary
by MITRE • 03/21/2022
Multiple versions of GARO Wallbox GLB/GTB/GTC are affected by unauthenticated command injection. The url parameter of the function module downloadAndUpdate is vulnerable to an command Injection. Unfiltered user input is used to generate code which then gets executed when downloading new firmware.
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Analysis
by VulDB Data Team • 03/23/2022
The vulnerability CVE-2021-45876 represents a critical command injection flaw in GARO Wallbox GLB/GTB/GTC devices that affects multiple firmware versions. This vulnerability resides within the downloadAndUpdate function's url parameter processing within the function module, creating a pathway for remote attackers to execute arbitrary commands on affected devices. The flaw stems from inadequate input validation and sanitization, where user-supplied URL parameters are directly incorporated into system commands without proper filtering or escaping mechanisms. This design oversight allows malicious actors to inject command sequences that the system then executes with elevated privileges, potentially compromising the entire device and its operational environment.
The technical implementation of this vulnerability aligns with CWE-77, which specifically addresses command injection flaws where unvalidated user input is used to construct command strings that are then executed by the system. The attack vector is particularly concerning as it requires no authentication, making it accessible to anyone who can reach the device's network interface. The vulnerability operates at the application layer, targeting the firmware update mechanism that should be a secure and controlled process. When an attacker crafts a malicious URL parameter containing shell commands, these commands get executed during the firmware download process, potentially enabling complete system compromise including privilege escalation and persistent access.
The operational impact of this vulnerability extends beyond simple device compromise to encompass broader security implications for electric vehicle charging infrastructure. Affected GARO Wallbox devices could be exploited to gain unauthorized access to network resources, potentially serving as a foothold for lateral movement within corporate or residential networks. The unauthenticated nature of the attack means that attackers can exploit this vulnerability without requiring valid credentials, making it particularly dangerous in environments where physical access control is not sufficient. Additionally, the vulnerability affects the firmware update process itself, which could be leveraged to install malicious firmware or disable security features, potentially leading to service disruption or unauthorized charging sessions that could result in financial loss.
Mitigation strategies for CVE-2021-45876 should prioritize immediate firmware updates from GARO if available, as this represents the most effective defense against exploitation. Network segmentation and access control measures should be implemented to limit exposure of these devices to untrusted networks, while firewall rules should restrict access to the specific ports and endpoints associated with the firmware update functionality. The implementation of input validation and sanitization controls within the application code is essential, ensuring that all user-supplied parameters undergo proper filtering before being processed. Organizations should also consider deploying intrusion detection systems to monitor for suspicious network traffic patterns that might indicate exploitation attempts, particularly focusing on unusual URL parameter patterns or command execution signatures. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1078.004 (Valid Accounts: Cloud Accounts) if the devices are integrated into cloud management systems, highlighting the need for comprehensive security monitoring and access control measures across the entire operational environment.