CVE-2019-12326 in R50P
Summary
by MITRE
Missing file and path validation in the ringtone upload function of the Akuvox R50P VoIP phone 50.0.6.156 allows an attacker to upload a manipulated ringtone file, with an executable payload (shell commands within the file) and trigger code execution.
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Analysis
by VulDB Data Team • 11/05/2023
The CVE-2019-12326 vulnerability represents a critical security flaw in the Akuvox R50P VoIP phone firmware version 50.0.6.156, where insufficient input validation during the ringtone upload process creates a pathway for remote code execution. This vulnerability stems from the absence of proper file type and path validation mechanisms within the device's web interface, allowing malicious actors to bypass normal security controls. The ringtone upload functionality, designed for legitimate user customization, becomes a vector for attackers to inject malicious payloads that can execute arbitrary shell commands on the device. The vulnerability specifically affects the device's handling of file uploads, where the system fails to properly validate the file extension, content type, or file path before processing the uploaded data. This oversight creates a dangerous condition where an attacker can upload a specially crafted file that contains executable code, effectively transforming the device into a potential command and control node.
The technical exploitation of this vulnerability follows a pattern that aligns with common web application attack vectors and can be mapped to CWE-434, which describes "Unrestricted Upload of File with Dangerous Type." The attack requires an authenticated user context to access the web interface, but once achieved, the attacker can leverage the lack of validation to upload a malicious ringtone file containing shell commands. The device's firmware processes this file without proper sanitization or verification, allowing the embedded code to execute with the privileges of the web server process. This scenario demonstrates a classic path traversal and file upload vulnerability where the attacker can manipulate file paths to place malicious code in locations where it can be executed, potentially leading to complete system compromise. The vulnerability also relates to ATT&CK technique T1059.007, which covers "Command and Scripting Interpreter: PowerShell," as the shell commands within the uploaded file can be executed through the device's command processing capabilities.
The operational impact of CVE-2019-12326 extends beyond simple privilege escalation, as it enables attackers to gain persistent access to VoIP infrastructure and potentially use the compromised device as a pivot point for further network exploration. The compromised device can serve as a foothold for attackers to conduct reconnaissance, establish command and control channels, or launch attacks against other networked devices. Organizations using Akuvox R50P devices may face significant security implications including unauthorized access to communication channels, potential data exfiltration, and disruption of voice services. The vulnerability's impact is particularly concerning in enterprise environments where VoIP systems serve as critical communication infrastructure, as it could lead to complete network compromise through lateral movement. The device's default configuration and lack of proper input validation make it especially susceptible to automated exploitation attempts, where attackers can craft payloads that automatically exploit this vulnerability without requiring extensive manual intervention.
Mitigation strategies for CVE-2019-12326 should prioritize immediate firmware updates from the vendor, which typically include enhanced input validation, proper file type checking, and restrictions on file paths that can be used during the upload process. Network segmentation and access control measures can help limit the impact of successful exploitation by restricting access to the device's web interface to authorized personnel only. Security monitoring should include detection of unusual file upload activities and command execution patterns within the network infrastructure. Implementing web application firewalls and content filtering solutions can provide additional layers of protection against malicious file uploads. Organizations should also conduct regular security assessments of VoIP infrastructure, including vulnerability scanning and penetration testing, to identify similar weaknesses in other networked devices. The remediation process must include thorough validation that the firmware update properly addresses the validation gaps and that all upload mechanisms within the device have been hardened against similar attack vectors. Additionally, implementing network access controls and disabling unnecessary services can reduce the attack surface and limit the potential impact of any successful exploitation attempts.