CVE-2007-3348 in DPH-540
Summary
by MITRE
The D-Link DPH-540/DPH-541 phone allows remote attackers to cause a denial of service (device outage) via a malformed SDP header in a SIP INVITE message.
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Analysis
by VulDB Data Team • 09/04/2018
The vulnerability identified as CVE-2007-3348 affects D-Link DPH-540 and DPH-541 VoIP phones, representing a significant security flaw in telecommunications infrastructure devices. These devices operate within enterprise and home networking environments where reliable voice communication is critical, making them attractive targets for attackers seeking to disrupt business operations or compromise network availability. The vulnerability specifically resides in the handling of Session Initiation Protocol (SIP) messages, which are fundamental to establishing and managing voice over IP communications.
The technical flaw manifests when the affected D-Link phones receive a malformed Session Description Protocol (SDP) header within a SIP INVITE message. This particular vulnerability falls under the category of improper input validation, where the device fails to properly sanitize or validate incoming SIP message parameters before processing them. The SDP header contains session information including media types, formats, and transport addresses that are essential for establishing VoIP connections. When an attacker crafts a malicious SIP INVITE message with malformed SDP data, the phone's processing logic becomes overwhelmed or encounters an unexpected state that causes the device to crash or become unresponsive.
The operational impact of this vulnerability extends beyond simple device disruption, as it can lead to complete service outages for users within the affected network. Network administrators may experience difficulties in maintaining consistent communication services, particularly in environments where these phones serve as primary communication endpoints. The remote nature of the attack means that adversaries can exploit this vulnerability from external network positions without requiring physical access or local network credentials. This characteristic aligns with attack patterns documented in the MITRE ATT&CK framework under the T1499 category for network denial of service, where attackers target network infrastructure to disrupt services. The vulnerability also relates to CWE-129, which describes improper validation of input boundaries, and CWE-20, which covers input validation issues in software systems.
The exploitation of this vulnerability demonstrates how seemingly minor protocol handling flaws can result in substantial operational consequences within enterprise environments. Organizations relying on these VoIP devices for business communication face potential financial losses due to extended downtime, emergency communication disruptions, and the costs associated with device replacement and network recovery. The vulnerability affects devices that are typically deployed in mission-critical communication scenarios, where service availability is paramount. Security professionals should note that this issue represents a classic example of how network infrastructure devices often lack robust input validation mechanisms, making them susceptible to exploitation through protocol manipulation attacks.
Mitigation strategies for this vulnerability should focus on implementing network segmentation and access control measures to limit exposure to external threats. Network administrators should consider deploying firewalls or intrusion prevention systems that can filter malformed SIP traffic before it reaches vulnerable endpoints. Device firmware updates from D-Link would provide the most effective long-term solution, addressing the root cause through proper input validation implementation. Additionally, monitoring network traffic for suspicious SIP message patterns can help identify potential exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date network security practices and demonstrates why organizations should prioritize security testing of network infrastructure devices, particularly those handling real-time communication protocols. Organizations should also consider implementing redundant communication systems to maintain business continuity in case of device-level service disruptions.