Примечания к выпуску для Cisco Cisco IOS Software Release 12.2(8)YM

The following sections contain important notes about Cisco IOS Release 12.2(8)YM1 that can apply to 
Cisco 800 series routers. (Also, see the 

Caveats describe unexpected behavior in Cisco IOS software releases. Severity 1 caveats are the most 
serious caveats, severity 2 caveats are less serious, and severity 3 caveats are the least serious of these 
three severity levels.

Caveats in Cisco IOS Releases 12.2 and 12.2 T are also in Cisco IOS Release 12.2(8)YM1. For 
information on caveats in Cisco IOS Release 12.2, see 

. For 

information on caveats in Cisco IOS Release 12.2 T, see 

. These 

two documents list severity 1 and 2 caveats and are located on 

CCO

and the Documentation CD-ROM. 

If you have an account with Cisco.com, you can also use the Bug Toolkit to find select caveats of any 
severity. To reach the Bug Toolkit, log in toCisco.com and click Service & Support: Technical 
Assistance Center: Tool Index: Bug Toolkit. Another option is to go to 

http://www.cisco.com/cgi-bin/Support/Bugtool/launch_bugtool.pl

.

Cisco IOS Release 12.2(8)YM1 is a rebuild release for Cisco IOS Release 12.2(8)YM. This section 
describes unexpected behavior that is fixed in Release 12.2(8)YM1.

Cisco routers and switches running Cisco IOS software and configured to process Internet Protocol 
version 4 (IPv4) packets are vulnerable to a Denial of Service (DoS) attack. A rare sequence of crafted 
IPv4 packets sent directly to the device may cause the input interface to stop processing traffic once the 
input queue is full. No authentication is required to process the inbound packet. Processing of IPv4 
packets is enabled by default. Devices running only IP version 6 (IPv6) are not affected. A workaround 
is available.

Cisco has made software available, free of charge, to correct the problem.

This advisory is available at

Cisco routers and switches running Cisco IOS software and configured to process Internet Protocol 
version 4 (IPv4) packets are vulnerable to a Denial of Service (DoS) attack. A rare sequence of crafted 
IPv4 packets sent directly to the device may cause the input interface to stop processing traffic once the 
input queue is full. No authentication is required to process the inbound packet. Processing of IPv4 
packets is enabled by default. Devices running only IP version 6 (IPv6) are not affected. A workaround 
is available.