ypserv security update

Updated ypserv packages fixing a denial of service vulnerability are now
available.

The ypserv package contains the Network Information Service (NIS) server.

A vulnerability has been discovered in the ypserv NIS server prior to
version 2.7. If a malicious client queries ypserv via TCP and subsequently
ignores the server's response, ypserv will block attempting to send the
reply. This results in ypserv failing to respond to other client requests.

Versions 2.7 and above of ypserv have been altered to fork a child for each
client request, thus preventing any one request from causing the server to
block.

Red Hat recommends that users of NIS upgrade to these packages, which
contain version 2.8.0 of ypserv and are therefore not vulnerable to this issue.

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-2003-0251
http://www.linux-nis.org/nis/ypserv/ChangeLog

DOS, NIS, ypserver