CVE-2018-17565 in GXP16xx VoIP
Summary
by MITRE
Shell Metacharacter Injection in the SSH configuration interface on Grandstream GXP16xx VoIP 1.0.4.128 phones allows attackers to execute arbitrary system commands and gain a root shell.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/21/2023
The vulnerability CVE-2018-17565 represents a critical shell metacharacter injection flaw discovered in the SSH configuration interface of Grandstream GXP16xx VoIP phones running firmware version 1.0.4.128. This vulnerability resides within the web-based management interface that allows administrators to configure Secure Shell settings for remote access to the device. The flaw stems from inadequate input validation and sanitization within the configuration handling mechanism, specifically when processing user-supplied parameters related to SSH server configuration. Attackers can exploit this vulnerability by crafting malicious input containing shell metacharacters that get executed within the context of the system shell, bypassing normal authentication and authorization controls.
The technical implementation of this vulnerability aligns with CWE-77 which describes improper neutralization of special elements used in a command. The affected device processes SSH configuration parameters without proper sanitization of shell metacharacters such as semicolons, ampersands, backticks, and pipes. When administrators configure SSH settings through the web interface, the system fails to properly escape or validate these inputs before incorporating them into shell commands. This creates a classic command injection scenario where attacker-controlled data flows directly into system command execution contexts, enabling arbitrary code execution with the privileges of the web server process. The vulnerability is particularly dangerous because it operates at the system level where the web interface has elevated privileges to modify core system configurations.
Operationally, this vulnerability poses severe risks to network security and device integrity within enterprise voice communication environments. An attacker who gains access to the web management interface can execute arbitrary commands with root privileges, potentially leading to complete device compromise and persistent access. The vulnerability can be exploited remotely without requiring authentication if the web interface is accessible from external networks, making it particularly attractive to threat actors. Once compromised, attackers can establish backdoors, exfiltrate sensitive communication data, modify device configurations to disrupt services, or use the device as a pivot point for further attacks within the internal network. The impact extends beyond individual device compromise to potential disruption of critical business communication infrastructure and violation of regulatory compliance requirements for telecommunications security.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Grandstream to address the input validation deficiencies. Network segmentation and access control measures must be implemented to restrict access to the web management interfaces, ensuring only authorized personnel can reach these administrative functions. Additional protective measures include disabling unnecessary services, implementing strong network access controls, and monitoring for suspicious command execution patterns. Organizations should also consider network intrusion detection systems that can identify anomalous shell command patterns and implement regular security assessments of VoIP infrastructure. The vulnerability demonstrates the importance of secure input handling in web applications and highlights the need for comprehensive security testing of network device management interfaces. According to ATT&CK framework, this vulnerability maps to T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, making it a critical target for both defensive and offensive security operations.