CVE-2006-0359 in eyeBeam SIP Softphone
Summary
by MITRE
Buffer overflow in CounterPath eyeBeam SIP Softphone allows remote attackers to (1) cause a denial of service (device crash) via SIP INVITE commands with a long header field name sent during startup and (2) cause a denial of service (device hang or crash) via SIP INVITE commands with a long header field name sent during a call.
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Analysis
by VulDB Data Team • 03/26/2019
The vulnerability described in CVE-2006-0359 represents a critical buffer overflow flaw within the CounterPath eyeBeam SIP Softphone implementation that poses significant operational risks to VoIP systems. This vulnerability specifically targets the softphone's handling of SIP INVITE commands, where the application fails to properly validate or limit the length of header field names in incoming SIP messages. The flaw manifests during two distinct operational phases: initial startup when the application processes incoming SIP INVITE commands, and during active call sessions when the same malformed input can trigger system instability. The buffer overflow occurs because the eyeBeam softphone does not implement proper bounds checking on header field names, allowing malicious actors to craft SIP messages with excessively long header field names that exceed the allocated buffer space.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-121, which describes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. In this case, the attacker crafts SIP INVITE messages containing header field names that exceed the maximum buffer capacity allocated by the eyeBeam application. When the softphone attempts to process these malformed headers, the excessive data overflows into adjacent memory segments, causing unpredictable behavior including application crashes, device hangs, or complete system failure. The vulnerability demonstrates a classic stack-based buffer overflow scenario where the application's memory management fails to account for variable-length input validation, creating a pathway for remote code execution or system compromise through denial of service attacks.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader security implications for enterprise communication infrastructures that rely on SIP-based softphones. Organizations utilizing eyeBeam softphones face potential business continuity risks as attackers can systematically target these devices to cause service outages, particularly during critical communication periods or when the softphone is actively processing calls. The vulnerability affects both the initial provisioning phase and ongoing operational use, meaning that attackers can potentially disrupt service at any point during the SIP communication lifecycle. From an attacker's perspective, this represents a low-effort, high-impact vector that requires minimal technical expertise to exploit while delivering substantial operational disruption. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through the exploitation of software vulnerabilities in communication protocols.
Mitigation strategies for this vulnerability should encompass both immediate defensive measures and long-term architectural improvements. Organizations should implement SIP message filtering at network boundaries to detect and block malformed INVITE commands containing excessively long header field names, effectively preventing exploitation before it reaches the vulnerable softphone. The recommended approach involves deploying network-based intrusion prevention systems capable of inspecting SIP protocol elements and applying rate limiting or content filtering rules. Additionally, system administrators should consider implementing application-level firewalls or proxy servers that can normalize SIP message formats before forwarding them to the eyeBeam softphone. The most effective long-term solution requires updating to patched versions of the eyeBeam software that include proper input validation and bounds checking mechanisms. Organizations should also establish monitoring protocols to detect unusual patterns of SIP INVITE traffic that may indicate attempted exploitation, while maintaining detailed logging of SIP communication to facilitate forensic analysis and incident response activities.