RHSA-2016:2591 - Security Advisory

Topic

An update for krb5 is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Low. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecure practice of sending passwords over the network in unencrypted form. It allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos key distribution center (KDC).

The following packages have been upgraded to a newer upstream version: krb5 (1.14.1). (BZ#1292153)

Security Fix(es):

• A NULL pointer dereference flaw was found in MIT Kerberos kadmind service. An authenticated attacker with permission to modify a principal entry could use this flaw to cause kadmind to dereference a null pointer and crash by supplying an empty DB argument to the modify_principal command, if kadmind was configured to use the LDAP KDB module. (CVE-2016-3119)
• A NULL pointer dereference flaw was found in MIT Kerberos krb5kdc service. An authenticated attacker could use this flaw to cause krb5kdc to dereference a null pointer and crash by making an S4U2Self request, if the restrict_anonymous_to_tgt option was set to true. (CVE-2016-3120)

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the updated packages, running Kerberos services (krb5kdc, kadmin, and kprop) will be restarted automatically.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.3 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 1135427 - kadmin.local -q with wrong value in -e option doesn't return nonzero return code
• BZ - 1146945 - RFE: Kerberos should support dropping configuration snippets to /etc/ and /usr
• BZ - 1183058 - krb5-server requires systemd-sysv when it shouldn't need to
• BZ - 1247261 - ksu asks for password even if called by root
• BZ - 1256735 - krb5kdc.log file is world-readable on IPA
• BZ - 1283902 - Remove krb5-server dependency on initscripts unless it is needed
• BZ - 1284987 - Please backport fix for interposer
• BZ - 1290239 - Update krb5 spec file with changes made in fedora
• BZ - 1292153 - Rebase krb5 to 1.14.x
• BZ - 1296241 - Chrome crash in spnego_gss_inquire_context()
• BZ - 1297591 - [backport] Fix some uses of installed files in the test suite
• BZ - 1313457 - krb5 selinux patch leaks memory
• BZ - 1314493 - Skip unnecessary mech calls in gss_inquire_cred
• BZ - 1319616 - CVE-2016-3119 krb5: null pointer dereference in kadmin
• BZ - 1340304 - otp module incorrectly overwrites as_key
• BZ - 1349042 - Incorrect length calculation in libkrad
• BZ - 1361050 - CVE-2016-3120 krb5: S4U2Self KDC crash when anon is restricted
• BZ - 1363690 - ssh login permission denied when ldap/krb5 is enabled via authconfig
• BZ - 1364993 - MS-KKDCP with TLS SNI requires HTTP Host header

CVEs

• CVE-2016-3119
• CVE-2016-3120

References

• https://access.redhat.com/security/updates/classification/#low