Omron WorldView Wnn Overflow makes it possible to gain a shell remotly.
SGI is currently working on patches. SGI Security Patches can be found at:
http://www.sgi.com/support/security/ and ftp://patches.sgi.com/support/free/security/patches/
Omron soft has Japanese support pages. The steps to minimize exposure are available at Stanford University advisory pages: http://www.stanford.edu/group/itss-c...s/00-1145.html
other references: http://online.securityfocus.com/advisories/4413 this page contains complete info and a list of available IRIX patches for this issue, including a list of links to the several version upgrade and patch servers.