MIT Kerberos Team reported following issue affecting MIT Kerberos 5 KDC with Kerberos 4 support enabled: CVE-2008-0063: The incoming krb4 message is copied into a fixed-size buffer on the stack, but the remainder of the buffer is left untouched, and the bounds checks use the size of the buffer, not the size of the data copied into it. Acknowledgements: Red Hat would like to thank MIT for reporting this issue.
See bug bug #432620 for patch.
This issue affects krb5 packages as shipped in Red Hat Enterprise Linux 2.1, 3, 4 and 5 and current versions of Fedora. Support for Kerberos v4 is not assumed by default by krb5kdc on Red Hat Enterprise Linux 5 and Fedora, however default configuration in kdc.conf enables this support explicitly (in nopreauth mode, which is assumed and configured as default on Red Hat Enterprise Linux 2.1, 3 and 4). Possible workaround -- disable v4 support if it's not needed -- in kdc.conf, set v4_mode to none.
Public now: http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2008-001.txt Lifting embargo.
krb5-1.6.1-9.fc7 has been submitted as an update for Fedora 7
krb5-1.6.2-14.fc8 has been submitted as an update for Fedora 8
krb5-1.6.1-9.fc7 has been pushed to the Fedora 7 stable repository. If problems still persist, please make note of it in this bug report.
krb5-1.6.2-14.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report.
This issue was addressed in: Red Hat Enterprise Linux: http://rhn.redhat.com/errata/RHSA-2008-0180.html http://rhn.redhat.com/errata/RHSA-2008-0181.html http://rhn.redhat.com/errata/RHSA-2008-0182.html http://rhn.redhat.com/errata/RHSA-2008-0164.html Fedora: https://admin.fedoraproject.org/updates/F7/FEDORA-2008-2637 https://admin.fedoraproject.org/updates/F8/FEDORA-2008-2647