Cisco Cisco IOS Software Release 12.4(23)

Cisco has released free software updates that address this vulnerability. Workarounds that mitigate 
this vulnerability are available.

This advisory is posted at 

.

CSCsi27540

Symptoms: A VSI session may become stuck in the “RESYNC_UNDERWAY” state, preventing 
LVC connections from being set up. This situation is not cleared automatically, and error messages 
are not flushed, as is shown in the output of the show controller vsi session command.

Conditions: This symptom is observed on a Cisco router that functions as a Label Switch Controller 
(LSC).

Workaround: There is no workaround. 

CSCsi60004

Multiple voice-related vulnerabilities are identified in Cisco IOS software, one of which is also 
shared with Cisco Unified Communications Manager. These vulnerabilities pertain to the following 
protocols or features:

Session Initiation Protocol (SIP)

Media Gateway Control Protocol (MGCP)

Signaling protocols H.323, H.254

Real-time Transport Protocol (RTP)

Facsimile reception

Cisco has made free software available to address these vulnerabilities for affected customers. Fixed 
Cisco IOS software listed in the Software Versions and Fixes section contains fixes for all 
vulnerabilities mentioned in this advisory.

There are no workarounds available to mitigate the effects of any of the vulnerabilities apart from 
disabling the protocol or feature itself.

This advisory is posted at 

. 

CSCsi67763

The U.S. Computer Emergency Response Team (US-CERT) has reported a network evasion 
technique using full-width and half-width unicode characters that affects several Cisco products. 
The US-CERT advisory is available at the following link:

By encoding attacks using a full-width or half-width unicode character set, an attacker can exploit 
this vulnerability to evade detection by an Intrusion Prevention System (IPS) or firewall. This may 
allow the attacker to covertly scan and attack systems normally protected by an IPS or firewall.

Cisco response is posted at the following link:

CSCsi84017

Symptoms: When you reload a Cisco 2600 series, the router may hang.

Conditions: This symptom is observed on a Cisco 2600 series when you attempt to run the 
c2600-entservices-mz image of Cisco IOS Release 12.4(9)T4. The symptom may also occur in other 
releases.

Workaround: There is no workaround.