CVE-2005-3804 in 7920 Wireless Ip Phone
Summary
by MITRE
Cisco IP Phone (VoIP) 7920 1.0(8) listens to UDP port 17185 to support a VxWorks debugger, which allows remote attackers to obtain sensitive information and cause a denial of service.
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Analysis
by VulDB Data Team • 06/11/2019
The vulnerability identified as CVE-2005-3804 affects Cisco IP Phone 7920 VoIP device running firmware version 1.0(8) and earlier. This issue stems from the device's improper configuration of network services that exposes a VxWorks debugger interface on UDP port 17185. The VxWorks operating system is a real-time embedded operating system commonly used in network equipment and industrial control systems, and its debugger interface is designed for development and troubleshooting purposes. However, when this interface remains accessible in production environments without proper authentication or access controls, it creates a significant security risk. The device's failure to properly restrict access to this debugging interface represents a critical flaw in the device's security architecture.
The technical flaw manifests as an insecure network service exposure that allows remote attackers to connect to the UDP port 17185 without authentication requirements. This vulnerability falls under CWE-284, which addresses improper access control, and specifically relates to CWE-276, concerning insecure file permissions and insecure default permissions. The VxWorks debugger interface provides extensive access to the device's internal memory, process information, and system configuration details. Attackers can leverage this access to extract sensitive information including system memory contents, device configuration parameters, and potentially credentials stored in memory. The debugger interface also enables attackers to manipulate the device's execution flow, potentially leading to arbitrary code execution or complete system compromise. This vulnerability directly violates the principle of least privilege and represents a fundamental failure in network device security hardening practices.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass full system compromise capabilities. Remote attackers can exploit this vulnerability to gain unauthorized access to the VoIP phone's internal systems, potentially leading to man-in-the-middle attacks on voice communications, unauthorized access to network resources, or use of the compromised device as a pivot point for further attacks within the network. The denial of service component of this vulnerability means that attackers can disrupt phone services by triggering system crashes or resource exhaustion through the debugger interface. This represents a significant risk in enterprise environments where VoIP systems form the backbone of communication infrastructure. The vulnerability affects the availability and integrity of voice services, potentially causing business disruption and compromising the confidentiality of voice communications. Network security frameworks such as those defined in the NIST Cybersecurity Framework are violated when devices expose debugging interfaces without proper access controls.
Mitigation strategies for CVE-2005-3804 require immediate implementation of network segmentation and access control measures. Organizations should implement firewall rules to block access to UDP port 17185 from untrusted networks and restrict access to authorized administrative networks only. Cisco recommends upgrading to firmware versions that either disable the VxWorks debugger interface or properly authenticate connections to it. Network administrators should conduct thorough inventory checks to identify all affected devices and apply firmware updates from Cisco's security advisories. The vulnerability demonstrates the importance of proper network device hardening and the principle of defense in depth, where multiple security controls work together to protect against various attack vectors. Security monitoring should include detection of unusual network traffic patterns on UDP port 17185, which could indicate exploitation attempts. This vulnerability also highlights the need for regular security assessments of embedded network devices and adherence to security best practices outlined in frameworks such as the CIS Critical Security Controls, which emphasize the importance of inventory management, vulnerability management, and secure configuration of network devices. The attack surface reduction approach recommended by MITRE ATT&CK framework should be applied to minimize exposure of debugging interfaces and other unnecessary network services on production network equipment.