CVE-2018-16217 in Ultra-elegant IP Phone SIP-T41P
Summary
by MITRE
The network diagnostic function (ping) in the Yeahlink Ultra-elegant IP Phone SIP-T41P (firmware 66.83.0.35) allows a remote authenticated attacker to trigger OS commands or open a reverse shell via command injection.
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Analysis
by VulDB Data Team • 09/24/2023
The vulnerability identified as CVE-2018-16217 affects the Yeahlink Ultra-elegant IP Phone SIP-T41P device running firmware version 66.83.0.35 and represents a critical command injection flaw within the device's network diagnostic functionality. This vulnerability specifically targets the ping command implementation that operates as part of the phone's network troubleshooting capabilities, making it accessible to authenticated users who can leverage this functionality to execute arbitrary operating system commands on the underlying system. The flaw stems from inadequate input validation and sanitization within the network diagnostic module, allowing maliciously crafted input to be interpreted and executed as system commands rather than being properly treated as data.
The technical nature of this vulnerability places it squarely within the scope of CWE-77 and CWE-94 categories, representing command injection and code execution weaknesses respectively. The attack vector requires an authenticated user context, meaning that an attacker must first establish valid credentials to access the device's administrative interface or network management functions before exploiting this vulnerability. This authentication requirement does not mitigate the severity of the flaw, as once authenticated, the attacker gains complete control over the device's operating system through the ping diagnostic function. The vulnerability allows for both arbitrary command execution and reverse shell establishment, providing attackers with persistent access to the device and potentially broader network access points.
The operational impact of this vulnerability extends beyond the immediate device compromise, as the SIP-T41P phone serves as a critical communication endpoint in enterprise and organizational networks. When exploited, this vulnerability enables attackers to execute commands with the privileges of the device's operating system, potentially allowing for network reconnaissance, data exfiltration, or further lateral movement within the network infrastructure. The ability to establish reverse shells provides attackers with persistent access, making this vulnerability particularly dangerous for environments where these devices are deployed in sensitive or critical network segments. The vulnerability affects not just individual devices but entire network infrastructures that rely on these telephony endpoints for communication, potentially compromising voice communication integrity and network security posture.
Mitigation strategies for CVE-2018-16217 should prioritize immediate firmware updates from Yeahlink to address the command injection vulnerability, as this represents the most effective solution to prevent exploitation. Network segmentation and access control measures should be implemented to restrict access to administrative functions and network diagnostic tools to authorized personnel only, reducing the attack surface available to potential adversaries. Regular security audits and vulnerability assessments should be conducted to identify similar command injection vulnerabilities in other networked devices and telephony systems. Additionally, monitoring network traffic for unusual command execution patterns and implementing intrusion detection systems can help identify exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1071.004 for application layer protocol, indicating that exploitation efforts would likely involve command execution and network protocol manipulation. Organizations should also consider implementing zero trust network access principles to minimize the impact of such vulnerabilities by ensuring least privilege access and continuous verification of device authenticity and integrity.