Updated kerberos packages fix various vulnerabilities

Updated Kerberos packages for IBM iSeries and pSeries systems fix a number
of vulnerabilities found in MIT Kerberos.

Kerberos is a network authentication system. The MIT Kerberos team
released an advisory describing a number of vulnerabilities that affect the
kerberos packages shipped by Red Hat. These vulnerabilities include:

An integer signedness error in the ASN.1 decoder before version 1.2.5
allows remote attackers to cause a denial of service (crash) via a large
unsigned data element length, which is later used as a negative value. The
Common Vulnerabilities and Exposures project has assigned the name
CAN-2002-0036 to this issue.

The Key Distribution Center (KDC) before version 1.2.5 allows remote,
authenticated attackers to cause a denial of service (crash) on KDCs within
the same realm using a certain protocol request that causes a null
dereference (CAN-2003-0058).

The Key Distribution Center (KDC) allows remote, authenticated attackers to
cause a denial of service (crash) on KDCs within the same realm using a
certain protocol request that causes an out-of-bounds read of an array
(CAN-2003-0072).

The Key Distribution Center (KDC) allows remote, authenticated attackers
to cause a denial of service (crash) on KDCs within the same realm using a
certain protocol request that causes the KDC to corrupt its heap
(CAN-2003-0082).

A vulnerability in Kerberos before version 1.2.3 allows users from one
realm to impersonate users in other realms that have the same inter-realm
keys (CAN-2003-0059).

The MIT advisory for these issues also mentions format string
vulnerabilities in the logging routines (CAN-2003-0060). Previous versions
of the kerberos packages from Red Hat already contain fixes for this issue.

Vulnerabilities have been found in the support for triple-DES keys in the
implementation of the Kerberos IV authentication protocol, which is
included in MIT Kerberos (CAN-2003-0139).

Vulnerabilities have been found in the Kerberos IV authentication protocol
that allow an attacker with knowledge of a cross-realm key, which is
shared with another realm, to impersonate any principal in that realm to
any service in that realm. This vulnerability can only be closed by
disabling cross-realm authentication in Kerberos IV (CAN-2003-0138).

Vulnerabilities have been found in the RPC library used by the kadmin
service in Kerberos 5. A faulty length check in the RPC library exposes
kadmind to an integer overflow, which can be used to crash kadmind
(CAN-2003-0028).

The Kerberos 5 network authentication system contains an RPC library which
includes an XDR decoder derived from Sun's RPC implementation. The Sun
implementation was recently demonstrated to be vulnerable to a heap
overflow. It is believed that the attacker needs to be able to
authenticate to the kadmin daemon for this attack to be successful
(CVE-2002-0391).

A stack buffer overflow was found in the implementation of the Kerberos v4
compatibility administration daemon (kadmind4), which is part of the the
MIT krb5 distribution, but not enabled or used by default in Red Hat Linux.
This vulnerability could be exploited to gain unauthorized root access to a
KDC host. The attacker does not need to authenticate to the daemon to
successfully perform this attack (CAN-2002-1235).

A problem has been found in the Kerberos ftp client. When retrieving a
file with a filename beginning with a pipe character, the ftp client will
pass the filename to the command shell in a system() call. This could
allow a malicious ftp server to write to files outside of the current
directory or execute commands as the user running the ftp client
(CAN-2003-0041).

All users of Kerberos are advised to upgrade to these errata packages,
which disable cross-realm authentication by default for Kerberos IV and
which contain backported patches that correct these issues.

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

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains
the
desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0036
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0391
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-1235
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0028
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0041
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0058
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0059
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0072
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0082
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0138
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0139
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2003-005-buf.txt
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2003-004-krb4.txt
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2003-003-xdr.txt
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2003-001-multiple.txt
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2002-002-kadm4.txt
http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2002-001-xdr.txt
http://www.kb.cert.org/vuls/id/258721

krb5