From the ethereal page, http://www.ethereal.com/appnotes/enpa-sa-00006.html SUMMARY Name: Potential issue with Ethereal 0.9.5 Docid: enpa-sa-00006 Date: August 20, 2002 Severity: High DETAILS Description: The ISIS protocol dissector in Ethereal 0.9.5 and earlier versions is susceptible to a buffer overflow. In order to determine which version of Ethereal you have installed, do one of the following: Load Ethereal and go to the Help->About Ethereal... menu item. From the command line run ethereal -vor tethereal -v(the "v" is lowercase"). Either action will display the the application version along with the libraries that Ethereal and Tethereal are linked with. If version "0.9.5" or prior is displayed, the application is susceptible. Impact: It may be possible to make Ethereal crash or hang by injecting a purposefully malformed packet onto the wire, or by convincing someone to read a malformed packet trace file. It may be possible to make Ethereal run arbitrary code by exploiting the buffer and pointer problems. Resolution: Upgrade to 0.9.6. If you are running a version prior to 0.9.6, you can disable the ISIS protocol dissector by selecting Edit->Protocols... and deselecting "isis" from the list. Regards, Jonas Eriksson