[RLSA_02-2006] OSU httpd for OpenVMS path and directory disclosure - is this a bug or a feature?

[rfdslabs@xxxxxxxxxxxxxxx]

         *** rfdslabs security advisory ***

Title: OSU httpd for OpenVMS path and directory disclosure - is this a bug or a 
feature? [RLSA_02-2006]
Versions: OSU/3.11alhpa, OSU/3.10a (probably others)
Vendor: David Jones, Ohio State University
(http://www.ecr6.ohio-state.edu/www/doc/serverinfo.html)
Date: 18 May 2006

Authors: Julio Cesar Fort <julio *NO_SPAM* rfdslabs com br>
         Iruata Souza, the VMS freak <iru.muzgo *NO_SPAM* gmail com>

   September 18th: HAPPY BIRTHDAY, MUZGO! :D

1. Introduction

   OSU is a http server for Compaq/HP (rest in peace, DEC) OpenVMS operating 
system. It supports a wide variety of TCP stacks for VMS like UCX, MultiNet, 
among others. Besides this OSU supports CGI (written in DCL), SSI and many 
others.

2. Details

 2.1 - Path disclosure (tested on OSU 3.11)

    This one is pretty simple. If one requests a non-existant file to the 
server it simply returns like this:

    Error:
    File /staff$disk/www_server/home/NONEXISTANT (/NONEXISTANT) could not be 
opened VMS especification:
staff$disk:[www_server.home]NONEXISTANT index.url present

    Exposing path information that, in our opinion, should not be exposed.


 2.2 - Directory and file disclosure

    This occurs by the faulty handling of wildcards (VMS '*' char) on URL 
specifications as in:

    http://muzgo.is.a.freak.foo.bar/a*/

    Which leads to the content of the first directory starting with the letter 
'a' being shown
and totally browsable. Sometimes there might be hidden or useful information:

    ----------------------------
    | Files                    |
    |                          |
    | ACRAPPY.DOC{stat error}  |
    | APROGRAM.EXE{stat error} |
    | AN.OBJ{stat error}       |
    | PR0N.XXX{stat error}     |
    ----------------------------

    Just a single click and you can view the content or download the exposed 
files. A smart attacker (not brazilian kiddies, of course) could create a very 
simple script to perform brute-force attack to guess directory names and access 
them directly.


3. Solution

    Nothing yet.


4. Timeline

     Apr 2006: Vulnerability detected;
  18 May 2006: Advisory written;
  09 Jun 2006: Vendor contacted;
  09 Jul 2006: No response from vendor;
  18 Sep 2006: Advisory released.

Thanks to barrossecurity.com, gotfault.net brothers, risesecurity.org, Lucien 
Rocha, Victor Galante, and friends everywhere.
Iruata Souza also would like to thank Diego Casati.

www.rfdslabs.com.br - computers, sex, human mind, music and more.
Recife, PE, Brazil