Cisco Cisco IOS Software Release 12.2
89
Caveats for Cisco IOS Release 12.2
OL-3513-16 Rev. G0
Resolved Caveats—Cisco IOS Release 12.2(26a)
IP Routing Protocols
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CSCeh13489
Symptoms: A router may reset its Border Gateway Protocol (BGP) session.
Conditions: This symptom is observed when a Cisco router that peers with other routers receives an
Autonomous System (AS) path with a length that is equal to or greater than 255.
Autonomous System (AS) path with a length that is equal to or greater than 255.
Workaround: Configure the bgp maxas limit command in such as way that the maximum length of
the AS path is a value below 255. When the router receives an update with an excessive AS path
value, the prefix is rejected and recorded the event in the log.
the AS path is a value below 255. When the router receives an update with an excessive AS path
value, the prefix is rejected and recorded the event in the log.
Miscellaneous
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CSCei61732
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.
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.
customers.
This advisory is posted at
Resolved Caveats—Cisco IOS Release 12.2(26a)
Cisco IOS Release 12.2(26a) is a rebuild release for Cisco IOS Release 12.2(26). The caveats in this
section are resolved in Cisco IOS Release 12.2(26a) but may be open in previous Cisco IOS releases.
section are resolved in Cisco IOS Release 12.2(26a) but may be open in previous Cisco IOS releases.
The following information is provided for each caveat:
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Symptoms: A description of what is observed when the caveat occurs.
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Conditions: The conditions under which the caveat has been known to occur.
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Workaround: Solutions, if available, to counteract the caveat.
Basic System Services
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CSCef46191
Symptoms: A specifically crafted Transmission Control Protocol (TCP) connection to a telnet or
reverse telnet port of a Cisco device running Internetwork Operating System (IOS) may block
further telnet, reverse telnet, Remote Shell (RSH), Secure Shell (SSH), and in some cases Hypertext
Transport Protocol (HTTP) access to the Cisco device. Telnet, reverse telnet, RSH and SSH sessions
established prior to exploitation are not affected.
reverse telnet port of a Cisco device running Internetwork Operating System (IOS) may block
further telnet, reverse telnet, Remote Shell (RSH), Secure Shell (SSH), and in some cases Hypertext
Transport Protocol (HTTP) access to the Cisco device. Telnet, reverse telnet, RSH and SSH sessions
established prior to exploitation are not affected.
All other device services will operate normally.
Conditions: User initiated specially crafted TCP connection to a telnet or reverse telnet port results
in blocking further telnet sessions. Whereas, services such as packet forwarding, routing protocols
and all other communication to and through the device remains unaffected.
in blocking further telnet sessions. Whereas, services such as packet forwarding, routing protocols
and all other communication to and through the device remains unaffected.
Workaround: The detail advisory is available at