Scientific Linux Security Update : xinetd on SL6.x i386/x86_64
Medium Nessus Plugin ID 64961
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionWhen 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.
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.
SolutionUpdate the affected xinetd and / or xinetd-debuginfo packages.