IRIX's fcagent daemon is vulnerable to a Denial of Service attack.

IRIX's (versions 6.4, 6.5 and 6.5.2) fcagent daemon is an RPC based daemon that services requests about status or
configuration of a FibreVault enclosure (a very fast fiber optics installation of Disks).
Fcagent is vulnerable to a remote Denial of Service attack that could cause the FibreVault to stop responding,
making the IRIX's Disk array inaccessible.

By sending a specific RPC packet to the fcagent daemon, the FibreVault configuration and status monitor can be
made inoperable. This causes all the disks inside the FibreVault to stop responding, sometimes resulting in a system
halt.

A patch for the fcagent daemon exists and SGI advises its customers to upgrade to IRIX 6.5.2.

IRIX's security home page can be found at: http://www.sgi.com/Support/security/security.html. 
Information on upgrading to IRIX 6.5.2 can be found at: http://support.sgi.com/news/irix2.html.