Brian Atkisson reported that the kadmind server on a master KDC was crashing due to certain requests from kadmin clients from krb5 1.8. This is due to check_handle() in server_stubs.c returning a failure if the clients tries to start with API version 3. The server frees the handle, and then attempts to dereference the handle when calling krb5_get_error_message(), at which point kadmind will usually segfault and crash.
This has already been fixed upstream in changeset 20485:
This was previously reported to Debian:
By the looks of the upstream reports, this is just a denial of service, nothing more. It was also assigned CVE-2010-0629.
Looking at the commit, this would have been fixed in 1.6.4, which means Fedora 11 is vulnerable.
This issue also does not affect Red Hat Enterprise Linux 4 or earlier as the variable in question (handle) isn't referenced after it is freed.
This issue does affect Red Hat Enterprise Linux 5.
This issue has been addressed in following products:
Red Hat Enterprise Linux 5
Via RHSA-2010:0343 https://rhn.redhat.com/errata/RHSA-2010-0343.html
krb5-1.6.3-29.fc11 has been submitted as an update for Fedora 11.
krb5-1.6.3-29.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.