Datasheet

160
Release Notes for Cisco IOS Release 12.1E on the Catalyst 6500 and Cisco 7600 Supervisor Engine and MSFC
OL-2310-11
Caveats
• Resolved General Caveats in Release 12.1(23)E, page 163
Open General Caveats in Release 12.1(23)E4
None.
Resolved General Caveats in Release 12.1(23)E4
• Cisco IOS may permit arbitrary code execution after exploitation of a heap-based buffer overflow
vulnerability. Cisco has included additional integrity checks in its software, as further described
below, that are intended to reduce the likelihood of arbitrary code execution.
Cisco has made free software available that includes the additional integrity checks for affected
customers.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20051102-timers.shtml.
This problem is resolved in Release 12.1(23)E4. (CSCei61732)
• Receipt of a Border Gateway Protocol (BGP) Autonomous System (AS) path with a length that is
equal to or greater than 255 might reset the BGP session. This problem is resolved in
Release 12.1(23)E4. (CSCeh13489)
Resolved General Caveats in Release 12.1(23)E3
• Policing might not be accurate for packets smaller than 82 bytes. This problem is resolved in
Release 12.1(23)E3. (CSCee78451)
• A document that describes how the Internet Control Message Protocol (ICMP) could be used to
perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol
(TCP) has been made publicly available. This document has been published through the Internet
Engineering Task Force (IETF) Internet Draft process, and is entitled “ICMP Attacks Against TCP”
(draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of
three types:
1. Attacks that use ICMP “hard” error messages.
2. Attacks that use ICMP “fragmentation needed and Don’t Fragment (DF) bit set” messages, also
known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP “source quench” messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections,
depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are
workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security
Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple
vendors whose products are potentially affected. Its posting can be found at:
http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
This problem is resolved in Release 12.1(23)E3. (CSCef44225, CSCef44699, CSCef60659,
CSCsa59600)