A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO acceptor for continuation tokens. An unauthenticated attacker could use this flaw to crash the server acceptor. It is reported that this issue affects version 1.5 and later. Upstream commit and further details: https://github.com/krb5/krb5/commit/524688ce87a15fc75f87efc8c039ba4c7d5c197b
Created krb5 tracking bugs for this issue: Affects: fedora-all [bug 1121879]
Successful exploitation of this flaw requires that attacker must provide at least one valid context token in the security context negotiation before sending the empty token.This can be done using unauthenticated AS-REQ as the first token and then sending the empty token which would case a crash of the server, at this point attacker is not authenticated.
Statement: (none)
krb5-1.11.3-24.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.
krb5-1.11.5-10.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
Are the krb5-libs packages for RHEL5 and RHEL6 affected by this vulnerability?
IssueDescription: A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO acceptor for continuation tokens. A remote, unauthenticated attacker could use this flaw to crash a GSSAPI-enabled server application.
This issue has been addressed in the following products: Red Hat Enterprise Linux 5 Via RHSA-2014:1245 https://rhn.redhat.com/errata/RHSA-2014-1245.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2014:1389 https://rhn.redhat.com/errata/RHSA-2014-1389.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2015:0439 https://rhn.redhat.com/errata/RHSA-2015-0439.html