CVE-2022-28575 in A7100RU
Summary
by MITRE • 05/05/2022
It is found that there is a command injection vulnerability in the setopenvpnclientcfg interface in TOTOlink A7100RU (v7.4cu.2313_b20191024) router, which allows attackers to execute arbitrary commands through a carefully constructed payload
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Analysis
by VulDB Data Team • 05/08/2022
The command injection vulnerability identified in CVE-2022-28575 affects the TOTOlink A7100RU router model running firmware version v7.4cu.2313_b20191024 and specifically targets the setopenvpnclientcfg interface. This vulnerability represents a critical security flaw that enables remote attackers to execute arbitrary commands on the affected device by crafting malicious payloads. The issue stems from insufficient input validation and sanitization within the router's web interface, particularly in the OpenVPN client configuration management functionality. Security researchers have identified that the vulnerability allows for arbitrary code execution through the manipulation of parameters passed to the setopenvpnclientcfg endpoint, potentially compromising the entire network infrastructure controlled by the compromised router. This type of vulnerability falls under CWE-77 which specifically addresses command injection flaws where user-supplied data is directly incorporated into system commands without proper sanitization or validation.
The technical implementation of this vulnerability occurs when an attacker submits malicious input through the setopenvpnclientcfg interface, which then gets processed and executed as part of a system command without adequate filtering or escaping mechanisms. The router's web server fails to properly sanitize user inputs, allowing special characters and command delimiters to be interpreted by the underlying operating system shell. This creates a pathway for attackers to inject additional commands that can manipulate the router's configuration, access sensitive data, or establish persistent access points within the network. The vulnerability is particularly concerning because it operates at the system level, potentially enabling attackers to gain root access to the device and leverage it as a foothold for further network infiltration activities. Network security professionals should note that this vulnerability can be exploited without authentication in many cases, making it especially dangerous for devices exposed to untrusted networks.
The operational impact of CVE-2022-28575 extends beyond simple command execution, as it fundamentally compromises the integrity and confidentiality of network communications managed by the affected router. Attackers can use this vulnerability to modify OpenVPN client configurations, potentially redirecting traffic through malicious servers or extracting sensitive information from the network. The compromised device may become part of a botnet, serve as a pivot point for internal network reconnaissance, or be used to conduct man-in-the-middle attacks against connected devices. Organizations with multiple TOTOlink A7100RU devices deployed in their networks face significant risk, as a single compromised device can provide attackers with access to the entire local network segment. This vulnerability aligns with several ATT&CK techniques including T1059.001 for command and scripting interpreter and T1566 for credential access through network infrastructure compromise. The potential for lateral movement and privilege escalation makes this vulnerability particularly attractive to sophisticated threat actors.
Mitigation strategies for CVE-2022-28575 should prioritize immediate firmware updates from TOTOlink, as the vendor has likely released patches addressing this specific vulnerability. Network administrators should implement network segmentation to limit the potential impact of a compromised device and monitor for unusual network traffic patterns that might indicate exploitation attempts. The implementation of web application firewalls and input validation controls can provide additional defense layers, though these measures should complement rather than replace proper firmware updates. Security teams should conduct comprehensive vulnerability assessments to identify all affected devices within their network infrastructure and implement network monitoring to detect potential exploitation attempts. Access controls should be strengthened to ensure that only authorized personnel can modify router configurations, and regular security audits should be performed to maintain awareness of potential vulnerabilities in network infrastructure. The vulnerability also underscores the importance of secure coding practices and input validation in embedded systems, as the flaw demonstrates how inadequate sanitization of user inputs can lead to critical system compromise. Organizations should consider implementing zero-trust network architectures to reduce the attack surface and limit the potential damage from such vulnerabilities.