CVE-2017-15614 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-outif variable in the pptp_client.lua file.
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Analysis
by VulDB Data Team • 12/22/2019
The vulnerability identified as CVE-2017-15614 affects TP-Link WVR WAR and ER series devices, representing a critical command injection flaw that enables remote authenticated administrators to execute arbitrary code on affected systems. This vulnerability resides within the pptp_client.lua file where the new-outif variable is improperly handled, creating an exploitable condition that allows attackers with administrative credentials to inject malicious commands into the system's command execution pipeline. The flaw demonstrates a classic lack of proper input validation and sanitization, which falls under the CWE-77 attack pattern classification for command injection vulnerabilities.
The technical implementation of this vulnerability occurs when an authenticated administrator submits crafted input through the new-outif parameter within the pptp_client.lua script. The device fails to properly sanitize or escape special characters in this variable before incorporating it into system commands, creating a direct path for command injection attacks. This allows an attacker with valid administrative credentials to manipulate the underlying system by executing arbitrary shell commands with the privileges of the web server process. The vulnerability operates at the application layer and can be exploited remotely, making it particularly dangerous as it requires no physical access or additional authentication mechanisms beyond legitimate administrative credentials.
From an operational impact perspective, this vulnerability compromises the integrity and confidentiality of affected networks by enabling unauthorized code execution. An attacker who gains administrative access through legitimate means can leverage this flaw to escalate privileges, install backdoors, modify network configurations, or exfiltrate sensitive data from the device. The attack surface extends beyond individual device compromise to potentially enable lateral movement within network infrastructures where these devices serve as gateways or routers. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, representing a significant security risk for organizations relying on TP-Link networking equipment.
Organizations should implement immediate mitigations including applying official firmware updates from TP-Link, which address the command injection vulnerability through proper input validation and sanitization of user-supplied parameters. Network segmentation strategies should be employed to limit administrative access to only necessary personnel, while implementing multi-factor authentication and role-based access controls to reduce the attack surface. Regular security audits should verify proper input handling in all network device configurations, and monitoring systems should be deployed to detect anomalous command execution patterns that may indicate exploitation attempts. The vulnerability also underscores the importance of secure coding practices and input validation as outlined in OWASP Top 10 and NIST Cybersecurity Framework guidelines for preventing similar injection attacks in network infrastructure devices.