sdtcm_convert

[jen () ETTNET SE (Joel Eriksson)]

Hello Bugtraq readers.

There have been security holes in sdtcm_convert before, as with most CDE
programs it seem. Studying some truss-output I think I found yet another
one.

If one of the following files does not exist and sdtcm_convert is SUID you
are probably vulnerable (I say probably since I haven't tested exploiting
the bug):

  /usr/spool/calendar/.lock.convert.<hostname>
  /usr/spool/calendar/.lock.<hostname>

They are opened with O_WRONLY|O_CREAT and mode 0660, EUID = 0. This means
that a symbolic link from them to anywhere would either create or overwrite
the destination file when sdtcm_convert is run, the file would be owned by
root, but by YOUR group. Since it is also writeable by group (0660) the
user exploiting this vulnerability also have write access to the file..

It does not take much imagination to gain root with this..

--
Joel Eriksson                                              jen () ettnet se
Security Consultant