Datasheet
135
Release Notes for Cisco IOS Release 12.1E on the Catalyst 6500 and Cisco 7600 Supervisor Engine and MSFC
OL-2310-11
Caveats
• A Cisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In
order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL
protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained
Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the
confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow
an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
–
Processing ClientHello messages, documented as Cisco bug ID CSCsb12598
–
Processing ChangeCipherSpec messages, documented as Cisco bug ID CSCsb40304
–
Processing Finished messages, documented as Cisco bug ID CSCsd92405
Cisco has made free software available to address these vulnerabilities for affected customers. There
are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml.
Note Another related advisory has been posted with this advisory. This additional advisory also
describes a vulnerability related to cryptography that affects Cisco IOS. This related advisory is
available at the following link:
http://www.cisco.com/warp/public/707/cisco-sa-20070522-crypto.shtml.
A combined software table for Cisco IOS is available to aid customers in choosing a software
releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is
available at the following link:
http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.
This problem is resolved in Release 12.1(26)E8. (CSCsb12598, CSCsb40304, CSCsd92405)
• Closing a Telnet session may cause a reload. This problem is resolved in Release 12.1(26)E8.
(CSCds33629)
• In certain LAN topologies, the PIM assert mechanism can cause an upstream router to erroneously
remove downstream interfaces from output interface lists. When this situation occurs, it causes
multicast traffic to be dropped. This problem occurs when two or more upstream routers with routes
to the same rendezvous point or traffic source are connected to the same LAN segment as two
different downstream routers. The problem occurs when the two downstream routers select different
upstream routers as their next hop. This problem is resolved in Release 12.1(26)E8. (CSCeh17756)
• A vulnerability exists in the IOS HTTP server in which HTML code inserted into dynamically
generated output, such as the output from a show buffers command, will be passed to the browser
requesting the page. This HTML code could be interpreted by the client browser and potentially
execute malicious commands against the device or other possible cross-site scripting attacks.
Successful exploitation of this vulnerability requires that a user browse a page containing dynamic
content in which HTML commands have been injected.
Cisco will be making free software available to address this vulnerability for affected customers.
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-20051201-http.shtml
This problem is resolved in Release 12.1(26)E8. (CSCsc64976)