CVE-2018-19978 in COMfort 1200 IP Phone
Summary
by MITRE
A buffer overflow vulnerability in the DHCP and PPPOE configuration interface of the Auerswald COMfort 1200 IP phone 3.4.4.1-10589 allows a remote attacker (authenticated as simple user in the same network as the device) to trigger remote code execution via a POST request (ManufacturerName parameter) to the web server on the device. The web server is running with root privileges and the injected code will also run with root privileges.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/25/2023
The CVE-2018-19978 vulnerability represents a critical buffer overflow flaw in the Auerswald COMfort 1200 IP phone firmware version 3.4.4.1-10589, specifically affecting the DHCP and PPPOE configuration interface. This vulnerability resides within the web server component that handles HTTP POST requests, making it accessible through the device's network interface. The flaw manifests when processing the ManufacturerName parameter in a POST request, where insufficient input validation allows an attacker to exceed the allocated buffer space and overwrite adjacent memory regions. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of insecure input handling in web applications. The vulnerability is particularly concerning because it requires only local network access and basic user authentication, making it exploitable within the same network segment as the target device.
The technical exploitation of this vulnerability demonstrates how a simple parameter injection can lead to complete system compromise. When an attacker crafts a malicious POST request containing an oversized ManufacturerName parameter, the web server's insufficient bounds checking allows memory corruption to occur. This memory corruption can overwrite critical program execution pointers, enabling the attacker to redirect code execution flow and inject arbitrary commands. The web server component operates with root privileges, meaning that any code executed through this vulnerability inherits the same elevated permissions, creating a direct path to full system compromise. The attack vector is particularly dangerous because it leverages the device's legitimate web interface, making it difficult to distinguish from normal traffic and allowing for stealthy exploitation.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete network compromise and potential lateral movement capabilities. An authenticated attacker within the same network segment can gain root access to the IP phone, potentially using it as a foothold for attacking other networked devices. This vulnerability violates fundamental security principles by allowing privilege escalation from a simple user account to system administrator level access without requiring additional authentication or specialized tools. The implications are significant for enterprise environments where IP phones are often deployed without proper network segmentation, potentially allowing attackers to pivot from voice communication systems to broader network infrastructure. The vulnerability also demonstrates poor security practices in embedded device development, where web servers are improperly configured to run with elevated privileges and lack proper input sanitization mechanisms.
Mitigation strategies for CVE-2018-19978 should focus on immediate firmware updates from the vendor, as this vulnerability affects a specific firmware version that likely contains a patch. Network segmentation should be implemented to isolate voice communication devices from critical network segments, reducing the attack surface for lateral movement. Access controls should be strengthened through authentication mechanisms and network access control lists that restrict which devices can communicate with the IP phone interfaces. The vulnerability also highlights the importance of input validation and secure coding practices, with recommendations to implement proper bounds checking, use of secure string handling functions, and privilege separation in embedded web server implementations. Organizations should also consider implementing network monitoring to detect anomalous POST request patterns that might indicate exploitation attempts, and establish incident response procedures specifically addressing voice communication device compromises. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date firmware in networked embedded devices, as unpatched systems represent persistent security risks that can be exploited to gain unauthorized access to entire network infrastructures.