COMMAND
UltraBoard
SYSTEMS AFFECTED
UltraBoard V1.6X
PROBLEM
Rudi Carell found following. He found some interesting things in
the "old" UltraBoard-Forum scripts (UltraBoard V 1.6). By using
the good old NullByte(\000) its possible to open "any" file on
the webserver(with its permissions) running the "UltraBoard"
forum-software. cgi-script:
UltraBoard.pl || UltraBoard.cgi
Variables:
Action=PrintableTopic
Post=[path_including_".."_to_any_file][***NULLBYTE***]
Board=[valid_board]
Idle=10
Sort=0
Order=Descend
Page=0
Session=
hmm ... EOF
Juan M. Bello Rivas added following. There's even more fun
availiable with old versions of ultraboard (and latest beta of
ultraboard 2000 is also vulnerable to this?). You can bring the
web server to its knees by issuing a request to the CGI like this:
QUERY_STRING=Session=../UltraBoard.pl%00%7c
It will start forking instances of the CGI until it eats all the
resources of the machine.
SOLUTION
Newer version fixes this?