Specifications

1408
Cross-Platform Release Notes for Cisco IOS Release 12.0S
OL-1617-14 Rev. Q0
Resolved Caveats—Cisco IOS Release 12.0(27)S
• CSCed03356
Symptoms: The deletion of an ATM subinterface may occasionally cause a secondary Performance
Routing Engine (PRE) to reload.
Conditions: This symptom is observed on a Cisco 10000 series that has two PREs that are
configured for high availability.
Workaround: There is no workaround. However, the symptom does not affect performance. The
primary PRE continues to forward traffic. The secondary PRE will reload if it is configured to do so.
• CSCed27956
A vulnerability in the Transmission Control Protocol (TCP) specification (RFC793) has been
discovered by an external researcher. The successful exploitation enables an adversary to reset any
established TCP connection in a much shorter time than was previously discussed publicly.
Depending on the application, the connection may get automatically re-established. In other cases,
a user will have to repeat the action (for example, open a new Telnet or SSH session). Depending
upon the attacked protocol, a successful attack may have additional consequences beyond
terminated connection which must be considered. This attack vector is only applicable to the
sessions which are terminating on a device (such as a router, switch, or computer) and not to the
sessions that are only passing through the device (for example, transit traffic that is being routed by
a router). In addition, this attack vector does not directly compromise data integrity or
confidentiality.
All Cisco products which contain TCP stack are susceptible to this vulnerability.
This advisory is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-ios.shtml, and it describes this
vulnerability as it applies to Cisco products that run Cisco IOS® software.
A companion advisory that describes this vulnerability for products that do not run Cisco IOS
software is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-nonios.shtml.
• CSCed38527
A vulnerability in the Transmission Control Protocol (TCP) specification (RFC793) has been
discovered by an external researcher. The successful exploitation enables an adversary to reset any
established TCP connection in a much shorter time than was previously discussed publicly.
Depending on the application, the connection may get automatically re-established. In other cases,
a user will have to repeat the action (for example, open a new Telnet or SSH session). Depending
upon the attacked protocol, a successful attack may have additional consequences beyond
terminated connection which must be considered. This attack vector is only applicable to the
sessions which are terminating on a device (such as a router, switch, or computer) and not to the
sessions that are only passing through the device (for example, transit traffic that is being routed by
a router). In addition, this attack vector does not directly compromise data integrity or
confidentiality.
All Cisco products which contain TCP stack are susceptible to this vulnerability.
This advisory is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-ios.shtml, and it describes this
vulnerability as it applies to Cisco products that run Cisco IOS® software.
A companion advisory that describes this vulnerability for products that do not run Cisco IOS
software is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-nonios.shtml.