The IRIX's /usr/lib/desktop/permissions tool is a suid and sgid root applications normally used by users to modify permissions of their files and files they are privileged for. A vulnerability in the permissions tool allows local malicious users to modify the permissions of any file on the system.
This is SGI SCR # 265071.
If you attempt to change the permissions of a file you don't have privileges for the permissions tool will prompt you for the name and password of a privileged user. But the permission changes are made to the target file before the tool prompts you for the password if you double click "Apply".
Run /usr/lib/desktop/permissions aganist the file which permissions you want to modify. Change the permissions. Click on the 'Apply' button twice before the dialog box appears asking you for a username and password. Click the 'Cancel' button.