CVE-2017-15633 in WVR
Summary
by MITRE
TP-Link WVR, WAR and ER devices allow remote authenticated administrators to execute arbitrary commands via command injection in the new-ipgroup variable in the session_limits.lua file.
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Analysis
by VulDB Data Team • 12/22/2019
The vulnerability CVE-2017-15633 represents a critical command injection flaw affecting TP-Link WVR, WAR, and ER series network devices. This security weakness resides within the session_limits.lua file where the new-ipgroup variable fails to properly sanitize user input, creating an avenue for remote authenticated attackers to execute arbitrary system commands. The vulnerability specifically targets administrative accounts that have authenticated access to the device's management interface, making it particularly dangerous as it leverages legitimate administrative privileges to escalate attacks. The flaw stems from inadequate input validation and improper parameter handling within the device's web-based management system, allowing attackers to inject malicious commands that are then executed with the privileges of the authenticated administrative user.
From a technical perspective, this vulnerability maps directly to CWE-77 which describes command injection flaws where untrusted data is incorporated into system commands without proper sanitization. The attack vector requires an authenticated administrative session, meaning the attacker must first obtain valid credentials or exploit another vulnerability to gain administrative access. Once authenticated, the attacker can manipulate the new-ipgroup parameter in the session_limits.lua file to inject malicious commands that get executed by the underlying operating system. This type of vulnerability enables attackers to perform actions such as creating backdoors, modifying system configurations, accessing sensitive data, or even completely compromising the device's functionality. The command injection occurs at the application layer where user-supplied parameters are directly passed to system execution functions without proper encoding or validation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with persistent access to network infrastructure devices that often serve as critical points in network security architectures. These TP-Link devices are commonly deployed in enterprise environments for wireless access and network management, making them attractive targets for attackers seeking to establish footholds within larger networks. The vulnerability allows for remote code execution capabilities that can be used to establish persistent access, exfiltrate network data, or pivot to other network segments. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where adversaries use legitimate system tools to execute malicious commands. The impact is particularly severe because the device's administrative interface is typically accessible over the network, and the attack can be performed remotely without requiring physical access.
Mitigation strategies for CVE-2017-15633 should prioritize immediate firmware updates from TP-Link to address the command injection vulnerability. Network administrators should implement strict access controls and ensure that administrative credentials are properly secured with strong authentication mechanisms including multi-factor authentication. Regular security audits should verify that no unauthorized administrative sessions exist and that all network devices are running patched firmware versions. Network segmentation and monitoring should be implemented to detect suspicious command execution patterns or unusual administrative activities. The vulnerability also highlights the importance of secure coding practices including input validation, parameter sanitization, and proper error handling in web applications. Organizations should conduct regular vulnerability assessments of their network infrastructure and maintain up-to-date security patches to prevent exploitation of similar command injection vulnerabilities in other network devices. Additionally, implementing network monitoring solutions that can detect anomalous command execution patterns will help identify potential exploitation attempts before they result in successful compromises.