krb5 security update

CentOS Errata and Security Advisory CESA-2016:0493

Kerberos is a networked authentication system which allows clients and
servers to authenticate to each other with the help of a trusted third
party, the Kerberos KDC.

A memory leak flaw was found in the krb5_unparse_name() function of the MIT
Kerberos kadmind service. An authenticated attacker could repeatedly send
specially crafted requests to the server, which could cause the server to
consume large amounts of memory resources, ultimately leading to a denial
of service due to memory exhaustion. (CVE-2015-8631)

An out-of-bounds read flaw was found in the kadmind service of MIT
Kerberos. An authenticated attacker could send a maliciously crafted
message to force kadmind to read beyond the end of allocated memory, and
write the memory contents to the KDC database if the attacker has write
permission, leading to information disclosure. (CVE-2015-8629)

The CVE-2015-8631 issue was discovered by Simo Sorce of Red Hat.

All krb5 users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. After installing the
updated packages, running Kerberos services (krb5kdc, kadmin, and kprop)
will be restarted automatically.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2016-March/083929.html

Affected packages:
krb5-devel
krb5-libs
krb5-pkinit-openssl
krb5-server
krb5-server-ldap
krb5-workstation

Upstream details at:
https://access.redhat.com/errata/RHSA-2016:0493