Updated glibc packages fix vulnerabilities

Updated glibc packages that fix a number of vulnerabilites are now available.

The glibc package contains standard libraries that are used by
multiple programs.

An integer overflow is present in the xdrmem_getbytes() function of glibc
2.3.1 and earlier. Depending upon the application, this vulnerability
could cause buffer overflows and may be exploitable, leading to arbitrary
code execution.

Red Hat would like to thank eEye Digital Security for alerting us to this
issue.

An error in the calculation of memory needed for unpacking arrays in the
XDR decoder in glibc 2.2.5 and earlier can result in a heap buffer
overflow. Depending upon the application, this vulnerability may be
exploitable and lead to arbitrary code execution.

A read buffer overflow vulnerability exists in the glibc resolver code in
versions of glibc up to and including 2.2.5. The vulnerability is triggered
by DNS packets larger than 1024 bytes and can cause applications to crash.

A buffer overflow vulnerability has been found in the way the glibc
resolver handles the resolution of network names and addresses via DNS (as
per Internet RFC 1011). Version 2.2.5 of glibc and earlier versions are
affected. A system would be vulnerable to this issue if the "networks"
database in /etc/nsswitch.conf includes the "dns" entry. By default, Red
Hat Linux ships with "networks" set to "files" and is therefore not
vulnerable to this issue. (CAN-2002-0684)

All users should upgrade to these errata packages, which contain patches to
the glibc libraries and are therefore not vulnerable to these issues.

NOTE: Once the glibc upgrade has been completed, you must either reboot the
system or restart all programs on the system (for example, by using telinit
1 and then switching back to the original runlevel). Rebooting the system
or restarting the system programs is necessary to avoid vulnerable glibc
copies in memory. In addition, one cannot mix old NSS modules or libresolv
with upgraded NSS modules or libresolve in one running application.

Note also that, if sshd is running so that the other services can be
restarted remotely or for a remote reboot during an unattended glibc
upgrade, glibc will also restart sshd.

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-2002-0391
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0684
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-1146
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0028
http://www.kb.cert.org/vuls/id/738331

buffer, DNS, glibc, integer, nsswitch, overflow, resolv, resolver, RPC, strncpy, sun, XDR