CVE-2020-25217 in GRP261x
Summary
by MITRE • 03/29/2021
Grandstream GRP261x VoIP phone running firmware version 1.0.3.6 (Base) allows Command Injection as root in its administrative web interface.
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Analysis
by VulDB Data Team • 04/06/2021
The Grandstream GRP261x VoIP phone represents a critical security vulnerability classified as command injection in its administrative web interface. This vulnerability exists within firmware version 1.0.3.6 and allows authenticated attackers with administrative privileges to execute arbitrary commands with root-level permissions. The flaw stems from insufficient input validation and sanitization within the web interface's parameter handling mechanisms, creating an avenue for malicious command execution. The vulnerability is particularly concerning as it operates at the highest privilege level, enabling full system compromise and unauthorized access to all network services and data stored on the device.
Technical exploitation of this vulnerability occurs through the administrative web interface where user-supplied parameters are directly incorporated into system commands without proper sanitization. Attackers can manipulate input fields to inject malicious commands that are then executed by the underlying operating system with root privileges. This type of vulnerability maps directly to CWE-77 Command Injection, which is categorized under the Common Weakness Enumeration framework as a critical security flaw. The attack surface is limited to authenticated users with administrative access, but the privilege escalation potential makes this vulnerability extremely dangerous in environments where administrative credentials might be compromised or where attackers can obtain legitimate administrative access through social engineering or other means.
The operational impact of this vulnerability extends far beyond simple command execution, as it enables complete system compromise and persistent access to the VoIP infrastructure. An attacker with root access can modify system configurations, install backdoors, exfiltrate sensitive communication data, and potentially use the device as a pivot point for further attacks within the network. The vulnerability affects enterprise VoIP deployments where these devices are commonly used for voice communication, making it a prime target for attackers seeking to intercept communications or disrupt business operations. Network security monitoring becomes significantly more challenging as malicious commands can be executed silently without generating obvious network traffic patterns. The attack vector aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter, specifically focusing on the execution of system commands through web interfaces.
Mitigation strategies for this vulnerability require immediate firmware updates from Grandstream to address the command injection flaw and implement proper input validation throughout the web interface. Organizations should enforce strict access controls and limit administrative privileges to only essential personnel with proper authentication mechanisms. Network segmentation and monitoring of administrative access attempts can help detect potential exploitation attempts. Security teams should also implement regular vulnerability assessments and penetration testing to identify similar flaws in other network devices. The remediation process must include comprehensive testing of firmware updates to ensure compatibility and prevent service disruptions. Additionally, implementing web application firewalls and input validation controls at network perimeters can provide additional layers of protection against exploitation attempts. Given the severity of the vulnerability, immediate action is required to patch affected devices and establish monitoring procedures to detect any potential exploitation attempts.