xinetd (SL5)

Synopsis: Low: xinetd security and bug fix update
Advisory ID: SLSA-2013:1302-1
Issue Date: 2013-09-30
CVE Numbers: CVE-2012-0862

When xinetd services are configured with the “TCPMUX” or “TCPMUXPLUS”
type, and the tcpmux-server service is enabled, those services are
accessible via port 1. It was found that enabling the tcpmux-server
service (it is disabled by default) allowed every xinetd service,
including those that are not configured with the “TCPMUX” or “TCPMUXPLUS”
type, to be accessible via port 1. This could allow a remote attacker to
bypass intended firewall restrictions. (CVE-2012-0862)

This update also fixes the following bugs:

* Prior to this update, a file descriptor array in the service.c source
file was not handled as expected. As a consequence, some of the
descriptors remained open when xinetd was under heavy load. Additionally,
the system log was filled with a large number of messages that took up a
lot of disk space over time. This update modifies the xinetd code to
handle the file descriptors correctly and messages no longer fill the
system log.

* Prior to this update, services were disabled permanently when their CPS
limit was reached. As a consequence, a failed bind operation could occur
when xinetd attempted to restart the service. This update adds additional
logic that attempts to restart the service. Now, the service is only
disabled if xinetd cannot restart the service after 30 attempts.


– Scientific Linux Development Team