Kerberos page

This page describes Kerberos 4 also known as KTH-KRB.
If you're looking for Kerberos 5 (you probably should), see the Heimdal pages.

Our eBones distribution


2003-03-17: Security advisory regarding v4 cross-realm

All versions of the kerberos server are vulnerable to a protocol bug in the kerberos v4 cross-realm operation. Release 1.2.2 by default disables cross-realm in the server, and adds an option for enabling it. The long-term fix is to migrate to Kerberos v5. (heimdal)

See also the MIT advisory.

2002-10-23: Security advisory regarding kadmind

All versions of the kadmind daemon are vulnerable to a remote root exploit. Release 1.2.1 should fix this problem.

Release 1.2.2 is now available with:

Also includes these bug-fixes from 1.2.1:


You can pick up our source distribution of Kerberos 4. It is based on eBones (which is based on MIT Kerberos 4 patchlevel 9), but has been severely hacked and is known to work on the following systems (these are what we use it on):

Some part compile and work on:

Apart from the core Kerberos programs the distribution contains the following:

Pick up the source. Binaries are not provided by us in an organised manner, there might be binary snapshots on the ftp-server, but we don't guarantee that they are other than of pre-historic vintage. If you're desperate, you can check the FTP directory.

Contrib directory available with patches to different programs for supporting kerberos.

For Windows users, we recommend ktelnet.


Some documentation is available as: The manual is also available translated to Japanese.


Send all bug reports to

Mailing list

There is a mailing list for the users of this package. Send mail to to subscribe.

Other documents

There are some other documents available:
The Kerberos FAQ

The original paper on Kerberos.
Kerberos: An Authentication Service for Open Network Systems, Jennifer Steiner, Clifford Neuman, and Jeffrey I. Schiller, 1988

A more light approach to the matter. Quite readable.
Designing an Authentication System: a Dialogue in Four Scenes, Bill Bryant, 1988.

Postscript HTML

The original installation notes from Athena. Other than the source tree description, does not apply to our distribution,
Kerberos Installation Notes, Bill Bryant, Jennifer Steiner, and John Kohl, 1989.

Notes on how to setup and run a server. Mostly applies to our distribution, but we have made some changes to make things a bit more smooth.
Kerberos Operation Notes, Bill Bryant, and John Kohl, 1989.

There are also many other documents:
Limitations of the Kerberos Authentication System, Steven M. Bellovin, and Michael Merrit, 1991.

Workstation Services and Kerberos Authentication at Project Athena, Don Davis, and Ralph Swick, 1989.

Kerberos Authentication in Sun RPC, Carl Smith, 1993.

The Evolution of the Kerberos Authentication Service, John T. Kohl, B. Clifford Neuman, Theodore Y. Ts'o, 1992

Workstation Services and Kerberos Authentication at Project Athena, Don Davis, Ralph Swich, 1989