AUSCERT External Security Bulletin Redistribution

                ESB-2002.253 -- Ethereal Security Advisory
                   Potential issues with Ethereal 0.9.3
                                31 May 2002


        AusCERT Security Bulletin Summary

Product:                Ethereal 0.9.3
Vendor:                 NS Computer Software and Services P/L
Impact:                 Denial of Service
                        Execute Arbitrary Code/Commands
Access Required:        Remote

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Name: Potential issues with Ethereal 0.9.3
Docid: enpa-sa-00004
Date: May 19, 2002
Severity: High


Four potential security issues have been discovered in Ethereal 0.9.3:

* The SMB dissector could potentially dereference a NULL pointer in two cases.

* The X11 dissector could potentially overflow a buffer while parsing keysyms.

* The DNS dissector could go into an infinite loop while reading a malformed

* The GIOP dissector could potentially allocate large amounts of memory.

No known exploits exist "in the wild" at the present time for any of these issues.

Versions prior to 0.9.3 are also subject to these bugs. 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 -v
  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 "0.9.3"
or prior is displayed, the application is susceptible.


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.


Upgrade to 0.9.4.

If you are running a version prior to 0.9.4, you can disable the
dissectors for each of these protocols by selecting Edit->Protocols... and
deselecting them from the list.

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