[原文]Certain Cisco IOS releases in 12.2S based trains with maintenance release number 25 and later, 12.3T based trains, and 12.4 based trains reuse a Tcl Shell process across login sessions of different local users on the same terminal if the first user does not use tclquit before exiting, which may cause subsequent local users to execute unintended commands or bypass AAA command authorization checks, aka Bug ID CSCef77770.
IOS contains a flaw that may allow a malicious user to gain access to unauthorized privileges. The issue is triggered when a user ends a tclsh login session without using tclquit, and a subsequent local user re-uses the process. This flaw may lead to a loss of integrity.
Upgrade to the latest version available for your equipment, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.