VoIP Phones - Cisco 7xxx: Difference between revisions

Back up to the VoIP Configuring page
From AAISP Support Site
mNo edit summary
m (clean up, typos fixed: to it's → to its)
 
Line 2: Line 2:
[[file:Cisco7940.png||ALT=Cisco7940]]
[[file:Cisco7940.png||ALT=Cisco7940]]


==Phones and Versions Tested==
==Phones and Versions Tested==


{| class="wikitable"
{| class="wikitable"
Line 45: Line 45:
'''* Important *'''
'''* Important *'''


Whilst testing SIP41.8-5-4S it appears the phone/firmware is vulnerable to a SIP/UDP amplification attack where crafted SIP 'INVITE' packets sent on UDP 5600 cause the phone to respond to it's upstream SIP gateway with multiple SIP 2.0 '404' packets. Measured at a rate of approximately 20 packets/second, whilst not a major cause for concern with a single phone could potentially cause service issues where several phones are in use.
Whilst testing SIP41.8-5-4S it appears the phone/firmware is vulnerable to a SIP/UDP amplification attack where crafted SIP 'INVITE' packets sent on UDP 5600 cause the phone to respond to its upstream SIP gateway with multiple SIP 2.0 '404' packets. Measured at a rate of approximately 20 packets/second, whilst not a major cause for concern with a single phone could potentially cause service issues where several phones are in use.


This vulnerability is protected against by correct firewall protection/filtering limiting inbound UDP on SIP port 5600 to the phone to be exclusively from
This vulnerability is protected against by correct firewall protection/filtering limiting inbound UDP on SIP port 5600 to the phone to be exclusively from
the parent SIP service (e.g. voiceless.aa.net.uk - see the VoIP security/firewall section). '''It is not recommended to leave these phones connected to the internet without any protection.'''
the parent SIP service (e.g. voiceless.aa.net.uk - see the VoIP security/firewall section). '''It is not recommended to leave these phones connected to the internet without any protection.'''


==Configuration:==
==Configuration==





Latest revision as of 00:00, 15 March 2017

ALT=Cisco7940

Phones and Versions Tested

Cisco 7xxx Versions tested
Model Version Notes
7940 3.8.6


7940G SIP41.8-5-4S Appears stable


7940G SIP41.9-4-2SR1-1S Phone runs sluggish, reboots randomly, not recommended
Feature Notes
Supports 302 Redirect ?
Tested on FireBrick SIP Server Yes
IPv6 Support No


* Important *

Whilst testing SIP41.8-5-4S it appears the phone/firmware is vulnerable to a SIP/UDP amplification attack where crafted SIP 'INVITE' packets sent on UDP 5600 cause the phone to respond to its upstream SIP gateway with multiple SIP 2.0 '404' packets. Measured at a rate of approximately 20 packets/second, whilst not a major cause for concern with a single phone could potentially cause service issues where several phones are in use.

This vulnerability is protected against by correct firewall protection/filtering limiting inbound UDP on SIP port 5600 to the phone to be exclusively from the parent SIP service (e.g. voiceless.aa.net.uk - see the VoIP security/firewall section). It is not recommended to leave these phones connected to the internet without any protection.

Configuration

Firewall & Security

  • You will also want to set up firewall rules, as per the VoIP Firewall page.
  • Also see the VoIP Security page for information about securing your VoIP service.