Alerts This Week
Warning Icon 1 764
Alerts This Week
Warning Icon 1 764

Red Hat 7: RHSA-2015-2154-07 Moderate: krb5 Security Bug Fix

red hat
Calendar Grey November 19, 2015
Dist Redhat Esm H88
The latest krb5 update resolves security vulnerabilities and improves features specifically for users of Red Hat Enterprise Linux 7.
Updated krb5 packages that fix two security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise Linux 7

Solution

Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

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

Summary

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).
It was found that the krb5_read_message() function of MIT Kerberos did not correctly sanitize input, and could create invalid krb5_data objects. A remote, unauthenticated attacker could use this flaw to crash a Kerberos child process via a specially crafted request. (CVE-2014-5355)
A flaw was found in the OTP kdcpreauth module of MIT kerberos. An unauthenticated remote attacker could use this flaw to bypass the requires_preauth flag on a client principal and obtain a ciphertext encrypted in the principal's long-term key. This ciphertext could be used to conduct an off-line dictionary attack against the user's password. (CVE-2015-2694)
The krb5 packages have been upgraded to upstream version 1.13.2, which provides a number of bug fixes and enhancements over the previous version. (BZ#1203889)
Notably, this update fixes the following bugs:
* Previously, the RADIUS support (libkrad) in krb5 was sending krb5 authentication for Transmission Control Protocol (TCP) transports multiple times, accidentally using a code path intended to be used only for unreliable transport types, for example User Datagram Protocol (UDP) transports. A patch that fixes the problem by disabling manual retries for reliable transports, such as TCP, has been applied, and the correct code path is now used in this situation. (BZ#1251586)
* Attempts to use Kerberos single sign-on (SSO) to access SAP NetWeaver systems sometimes failed. The SAP NetWeaver developer trace displayed the following error message:
No credentials were supplied, or the credentials were unavailable or inaccessible Unable to establish the security context
Querying SSO credential lifetime has been modified to trigger credential acquisition, thus preventing the error from occurring. Now, the user can successfully use Kerberos SSO for accessing SAP NetWeaver systems. (BZ#1252454)
All krb5 users are advised to upgrade to these updated packages, which correct these issues and add these enhancements.

Topics%20covered

Topics Covered

security advisory moderate bug fix red hat enterprise linux krb5

References

https://access.redhat.com/security/cve/CVE-2014-5355 https://access.redhat.com/security/cve/CVE-2015-2694 https://access.redhat.com/security/updates/classification/#moderate

Package List

Red Hat Enterprise Linux Client (v. 7):
Source: krb5-1.13.2-10.el7.src.rpm
x86_64: krb5-debuginfo-1.13.2-10.el7.i686.rpm krb5-debuginfo-1.13.2-10.el7.x86_64.rpm krb5-libs-1.13.2-10.el7.i686.rpm krb5-libs-1.13.2-10.el7.x86_64.rpm krb5-pkinit-1.13.2-10.el7.x86_64.rpm krb5-workstation-1.13.2-10.el7.x86_64.rpm
Red Hat Enterprise Linux Client Optional (v. 7):
x86_64: krb5-debuginfo-1.13.2-10.el7.i686.rpm krb5-debuginfo-1.13.2-10.el7.x86_64.rpm krb5-devel-1.13.2-10.el7.i686.rpm krb5-devel-1.13.2-10.el7.x86_64.rpm krb5-server-1.13.2-10.el7.x86_64.rpm krb5-server-ldap-1.13.2-10.el7.x86_64.rpm
Red Hat Enterprise Linux ComputeNode (v. 7):
Source: krb5-1.13.2-10.el7.src.rpm
x86_64: krb5-debuginfo-1.13.2-10.el7.i686.rpm krb5-debuginfo-1.13.2-10.el7.x86_64.rpm krb5-libs-1.13.2-10.el7.i686.rpm krb5-libs-1.13.2-10.el7.x86_64.rpm krb5-pkinit-1.13.2-10.el7.x86_64.rpm krb5-workstation-1.13.2-10.el7.x86_64.rpm
Red Hat Enterprise Linux ComputeNode Optional (v. 7):
x86_64: krb5-debuginfo-1.13.2-10.el7.i686.rpm krb5-debuginfo-1.13.2-10.el7.x86_64.rpm krb5-devel-1.13.2-10.el7.i686.rpm krb5-devel-1.13.2-10.el7.x86_64.rpm krb5-server-1.13.2-10.el7.x86_64.rpm krb5-server-ldap-1.13.2-10.el7.x86_64.rpm
Red Hat Enterprise Linux Server (v. 7):
Source: krb5-1.13.2-10.el7.src.rpm
aarch64:

Read the Full Advisory


Advisory ID: RHSA-2015:2154-07
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2015:2154.html
Issue date: 2015-11-19

Topic

Updated krb5 packages that fix two security issues, several bugs, and addvarious enhancements are now available for Red Hat Enterprise Linux 7.Red Hat Product Security has rated this update as having Moderate securityimpact. Common Vulnerability Scoring System (CVSS) base scores, which givedetailed severity ratings, are available for each vulnerability from theCVE links in the References section.

Topics%20covered

Topics Covered

security advisory moderate bug fix red hat enterprise linux krb5

Relevant Releases Architectures

Red Hat Enterprise Linux Client (v. 7) - x86_64

Red Hat Enterprise Linux Client Optional (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64

Red Hat Enterprise Linux Server (v. 7) - aarch64, ppc64, ppc64le, s390x, x86_64

Red Hat Enterprise Linux Workstation (v. 7) - x86_64

Bugs Fixed

1156144 - krb5 upstream test t_kdb.py failure

1163402 - kdb5_ldap_util view_policy does not shows ticket flags on s390x and ppc64

1164304 - Upstream unit tests loads the installed shared libraries instead the ones from the build

1185770 - Missing upstream test in krb5-1.12.2: src/tests/gssapi/t_invalid.c

1193939 - CVE-2014-5355 krb5: unauthenticated denial of service in recvauth_common() and others1203889 - RFE: Rebase krb5 in RHEL7.2 to krb5 1.13 (krb1.13.2) ...

1216133 - CVE-2015-2694 krb5: issues in OTP and PKINIT kdcpreauth modules leading to requires_preauth bypass

1222903 - [SELinux] AVC denials may appear when kadmind starts

1247608 - [RFE] Add support for multi-hop preauth mechs via |KDC_ERR_MORE_PREAUTH_DATA_REQUIRED| for RFC 6113 ("A Generalized Framework for Kerberos Pre-Authentication")

1247751 - krb5-config returns wrong -specs path

1247761 - RFE: Minor krb5 spec file cleanup and sync with recent Fedora 22/23 changes

1250154 - [s390x, ppc64, ppc64le]: kadmind does not accept ACL if kadm5.acl does not end with EOL

1251586 - KDC sends multiple requests to ipa-otpd for the same authentication

1259846 - KDC does not return proper client principal for client referrals

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.

Your message here