From: SecuriTeam <support@securiteam.com.>
To: [email protected]
Date: 22 Feb 2007 13:47:05 +0200
Subject: [NEWS] Cisco Unified IP Conference Station and IP Phone Vulnerabilities
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Cisco Unified IP Conference Station and IP Phone Vulnerabilities
------------------------------------------------------------------------
SUMMARY
Certain Cisco Unified IP Conference Station and IP Phone devices contain
vulnerabilities which may allow unauthorized users to gain administrative
access to vulnerable devices.
DETAILS
Cisco Unified IP Conference Station Administrative Bypass Vulnerability
Cisco Unified IP Conference Station 7935 and 7936 devices do not require a
password when a URL is accessed directly via the administrator HTTP
interface. There is a workaround for this vulnerability.
Cisco Unified IP Phone Default Account and Privilege Escalation
Vulnerabilities
Cisco Unified IP Phone 7906G, 7911G, 7941G, 7961G, 7970G and 7971G devices
contain a hard coded default user account with a default password which is
remotely accessible via a Secure Shell (SSH) server enabled on the phone.
This default user account may be leveraged to gain administrative access
to a vulnerable phone via a privilege escalation vulnerability. The
default user account may also execute commands causing a phone to become
unstable and result in a denial of service. The default user account can
not be disabled, removed or have its password changed. There are
mitigations available for these vulnerabilities.
Cisco has made free software available to address these issues for
affected customers.
Products Confirmed Not Vulnerable
Cisco Unified IP Phone 7902G, 7905, 7905G, 7910, 7912, 7912G, 7920, 7921G,
7940, 7960 and 7985 devices are not vulnerable to the default account and
privilege escalation vulnerability.
No other Cisco products are known to be vulnerable.
Details
Cisco Unified IP Conference Station Administrative Bypass Vulnerability
Cisco Unified IP Conference Station 7935 and 7936 devices provide
integrated speaker phone services for a networked environment. 7935/7936
devices can be managed via an administrative HTTP interface and/or a with
Cisco Unified CallManager (CUCM) system. The administrative HTTP interface
is protected by a user configurable password. If a user knows the direct
path to a management URL, it may be possible to access the administrative
HTTP interface without being prompted for authentication. The
vulnerability occurs because vulnerable IP Conference Station devices
incorrectly maintain the state of administrator login sessions. If an
administrator logs into a vulnerable device via the HTTP interface, the
administrator's credentials will be cached even after the administrator
logs out of the device. This leaves a window of opportunity for an
unauthorized user to gain complete administrative access to a vulnerable
device. If an administrator never accesses a potentially vulnerable device
via the HTTP interface, the device is not vulnerable to the authentication
bypass attack. It is possible to reset to an IP Conference Station to a
non-vulnerable state by power-cycling the device or performing a reboot
operation (not a reload operation) via the CUCM system which manages the
device. This defect is documented in Cisco Bug ID
<http://www.cisco.com/pcgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg26788>;
CSCsg26788 ( registered customers only) .
Cisco Unified IP Phone Default Account and Privilege Escalation
Vulnerabilities
Cisco Unified IP Phone 7906G, 7911G, 7941G, 7961G, 7970G and 7971G devices
provide integrated phone service for a networked environment. These IP
phones devices contain a hard coded default user account with a default
password that is used for debugging purposes and is embedded into the
phone's firmware. This default user account cannot be disabled, removed or
have its password changed. Due to an implementation error, it possible to
use the hard coded default user account to remotely access the Command
Line Interface (CLI) of a vulnerable IP phone via a phone's SSH server.
The SSH server is only supposed to authenticate user accounts which have
been created by an administrator. The SSH server may not be disabled. The
firmware update including the solution for this vulnerability prohibits
the default user account from accessing a phone via the SSH server, but
the default user account may still access the phone via the console serial
port. This defect is documented in Cisco Bug ID
<http://www.cisco.com/pcgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg34758>;
CSCsg34758 ( registered customers only) .
Using the default user account to access the CLI of a vulnerable IP phone
device (via SSH or the console serial port), an attacker can execute a
number of commands which may result in the escalation of privileges
leading to complete compromise of an affected IP phone or cause an IP
phone to become unstable and crash. These defects are documented in Cisco
Bug IDs
<http://www.cisco.com/pcgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg34789>;
CSCsg34789 ( registered customers only) and
<http://www.cisco.com/pcgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg42627>;
CSCsg42627 ( registered customers only) .
Impact:
Successful exploitation of the Conference Station administrative bypass or
IP Phone default account and privilege escalation vulnerabilities may
result in the complete compromise of a vulnerable device.
Workarounds:
For Cisco Unified Conference Station and IP Phone devices, the following
mitigations have been provided.
The effectiveness of any mitigation or fix is dependent on specific
customer situations such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied mitigation or fix
is the most appropriate for use in the intended network before it is
deployed.
Additional mitigations that can be deployed on Cisco devices within the
network are available in the Cisco Applied Intelligence companion document
for this advisory:
<http://www.cisco.com/warp/public/707/cisco-air-20070221-phone.shtml>;
http://www.cisco.com/warp/public/707/cisco-air-20070221-phone.shtml
Apply access control lists (ACLs) on routers, switches and firewalls that
filter traffic to vulnerable Conference Station and IP Phone devices so
that traffic is only allowed from stations that need to remotely
administer the devices.
It is possible to workaround the Cisco Unified IP Conference Station
Administrative Bypass vulnerability by ensuring that the administrative
HTTP interface is not used to manage any vulnerable devices. If the HTTP
interface must be used, vulnerable devices should be power cycled or
rebooted via a CUCM system after system changes are made.
ADDITIONAL INFORMATION
The information has been provided by <mailto:psirt@cisco.com.> Cisco
Systems Product Security Incident Response Team.
The original article can be found at:
<http://www.cisco.com/warp/public/707/cisco-sa-20070221-phone.shtml>;
http://www.cisco.com/warp/public/707/cisco-sa-20070221-phone.shtml
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