A vulnerability in Cisco Unified IP Phones could allow an unauthenticated, remote attacker to impersonate another user's phone if the Cisco Unified Communications Manager (CUCM) is in secure mode. This vulnerability is due to improper key generation during the manufacturing process that could result in duplicated manufactured keys installed on multiple devices. An attacker could exploit this vulnerability by performing a machine-in-the-middle attack on the secure communication between the phone and the CUCM. A successful exploit could allow the attacker to impersonate another user's phone. This vulnerability cannot be addressed with software updates. There is a workaround that addresses this vulnerability.

A vulnerability in the Web Access feature of Cisco IP Phones Series 7800 and Series 8800 could allow an unauthenticated, remote attacker to view sensitive information on an affected device. The vulnerability is due to improper access controls on the web-based management interface of an affected device. An attacker could exploit this vulnerability by sending malicious requests to the device, which could allow the attacker to bypass access restrictions. A successful attack could allow the attacker to view sensitive information, including device call logs that contain names, usernames, and phone numbers of users of the device.

Cisco 9900 Unified IP phones allow remote attackers to cause a denial of service (unregistration) via a crafted SIP header, aka Bug ID CSCul24898.

The firmware on Cisco Unified IP phones 8961, 9951, and 9971 uses weak permissions for memory block devices, which allows local users to gain privileges by mounting a device with a setuid file in its filesystem, aka Bug ID CSCui04382.

The image-upgrade functionality on Cisco 9900 Unified IP phones allows local users to gain privileges by placing shell commands in an unspecified parameter, aka Bug ID CSCuh10334.

Buffer overflow in the web-application interface on Cisco 9900 IP phones allows remote attackers to cause a denial of service (webapp interface outage) via long values in unspecified fields, aka Bug ID CSCuh10343.

The Serviceability servlet on Cisco 9900 IP phones does not properly restrict paths, which allows remote attackers to read arbitrary files by specifying a pathname in a file request, aka Bug ID CSCuh52810.