CVE-2018-0316 in IP Phone 6800
Summary
by MITRE
A vulnerability in the Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability exists because the firmware of an affected phone incorrectly handles errors that could occur when an incoming phone call is not answered. An attacker could exploit this vulnerability by sending a set of maliciously crafted SIP packets to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition. This vulnerability affects Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware if they are running a Multiplatform Firmware release prior to Release 11.1(2). Cisco Bug IDs: CSCvi24718.
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Analysis
by VulDB Data Team • 12/26/2024
The vulnerability identified as CVE-2018-0316 represents a critical denial of service weakness within Cisco's IP Phone 6800, 7800, and 8800 Series devices operating on Multiplatform Firmware. This security flaw specifically targets the Session Initiation Protocol call-handling mechanisms that govern how these telephony devices process incoming calls and manage error conditions. The vulnerability stems from improper error handling within the firmware implementation, creating a scenario where maliciously crafted SIP packets can trigger unintended system behavior. The affected devices are particularly susceptible when running firmware versions prior to Release 11.1(2), making this a firmware-specific vulnerability that impacts the operational integrity of enterprise communication systems.
The technical exploitation of this vulnerability occurs through the manipulation of SIP protocol packets that are transmitted to the affected phone devices. When an incoming call arrives and remains unanswered, the phone's firmware fails to properly manage the error condition that arises from this scenario. The malformed SIP packets crafted by an attacker specifically target this error handling mechanism, causing the device to enter an unexpected state that results in system reload. This behavior aligns with CWE-248, which addresses "Uncaught Exception" conditions in software implementations, where error states are not properly managed leading to system instability. The vulnerability demonstrates a classic example of how protocol implementation flaws can be leveraged for remote attack vectors without requiring authentication credentials.
The operational impact of CVE-2018-0316 extends beyond simple service disruption to create significant business continuity concerns for organizations relying on these communication devices. When an affected phone reloads unexpectedly, users experience temporary loss of communication capability that can cascade through enterprise networks where these devices serve as critical endpoints. The DoS condition, while temporary, can disrupt ongoing business operations and create reliability issues in mission-critical communication environments. This vulnerability particularly affects organizations using unified communications solutions where IP phones serve as primary communication tools for employees. The attack vector's remote nature means that adversaries can exploit this weakness from external network positions without requiring physical access or network credentials, making it a significant concern for network security teams.
Organizations should implement immediate mitigation strategies including firmware updates to Release 11.1(2) or later versions that contain the necessary patches for this vulnerability. Network segmentation and access control measures can help limit the potential attack surface by restricting unauthorized access to these devices from untrusted networks. Monitoring network traffic for suspicious SIP packet patterns can help detect potential exploitation attempts, while maintaining detailed logs of phone system behavior enables rapid incident response. The vulnerability also highlights the importance of regular firmware maintenance and security assessments for telephony infrastructure. From an ATT&CK framework perspective, this vulnerability maps to T1190 - Exploit Public-Facing Application and T1499 - Endpoint Termination, demonstrating how protocol-level weaknesses can be exploited to achieve system-level disruption. Organizations should also consider implementing network-based intrusion detection systems that can identify and alert on anomalous SIP traffic patterns that may indicate exploitation attempts.