Bugtraq mailing list archives

RE: [cgiwrap-users] RE: Format strings vuln in CGIwrap


From: "Neulinger, Nathan" <nneul () umr edu>
Date: Wed, 23 Apr 2003 12:04:43 -0500

In any case, I've changed this in cvs so as to avoid setting off any
future false-alarms. 

------------------------------------------------------------
Nathan Neulinger                       EMail:  nneul () umr edu
University of Missouri - Rolla         Phone: (573) 341-4841
Computing Services                       Fax: (573) 341-4216


-----Original Message-----
From: Neulinger, Nathan 
Sent: Wednesday, April 23, 2003 11:59 AM
To: b0f www.b0f.net; bugtraq () securityfocus com
Cc: cgiwrap-users () lists sourceforge net
Subject: [cgiwrap-users] RE: Format strings vuln in CGIwrap


This is not a security problem. This is a case of using an automated
tool to find these vulnerabilites and not attempting to understand the
code itself. 

Nowhere in the code is MSG_Error_General() passed anything 
other than a
static compiled-into-the-executable string. It's purely a utility
function to wrap common error text/footer/etc. around a 
generic string.

-- Nathan

------------------------------------------------------------
Nathan Neulinger                       EMail:  nneul () umr edu
University of Missouri - Rolla         Phone: (573) 341-4841
Computing Services                       Fax: (573) 341-4216


-----Original Message-----
From: security-bounces+nneul=umr.edu () lists umr edu 
[mailto:security-bounces+nneul=umr.edu () lists umr edu] On 
Behalf Of b0f www.b0f.net
Sent: Wednesday, April 23, 2003 11:06 AM
To: bugtraq () securityfocus com
Subject: Format strings vuln in CGIwrap




A locally and possibly remotely exploitable format
strings bug exists 
in cgiwrap available from  
http://cgiwrap.sourceforge.net/
http://sourceforge.net/projects/cgiwrap
http://www.freebsd.org/ports/security.html 

I. BACKGROUND

This is CGIWrap - a gateway that allows more secure
user access to
CGI programs on an HTTPd server than is provided by the
http server
itself. The primary function of CGIWrap is to make
certain that
any CGI script runs with the permissions of the user
who installed
it, and not those of the server.

CGIWrap works with NCSA httpd, Apache, CERN httpd,
NetSite Commerce
and Communications servers, and probably any other Unix
based web
server software that supports CGI.

II. DESCRIPTION

On line 91 of msgs.c the printf() function is used
incorrectly. Which 
results
in a format strings vulnerability.
<snip>
void MSG_Error_General(char *message)
{
        MSG_Header("CGIWrap Error", message);
        printf(message); 
        MSG_Footer();
        exit(1);
}
</snip>

The binaries in cgiwrap, (cgiwrap and nph-cgiwrap) are
installed setuid 
root.
Thus could make this format problem exploitable locally
to gain root 
privs or
possably remotely to gain root or the privs of the user
who owns the cgi 
script.

III. ANALYSIS
An attacker could exploit this issue to escalate privs
locally or 
remotely on
a server running cgiwrap.

IV. DETECTION

This is vulnerable in the latest version of cgiwrap
version 3.7.1 and 
properly
older versions(not checked). It would be exploitable on
any Linux/Unix 
based OS
running cgiwrap 

V. VENDOR
The vendor has not been contacted about this issue.

Regards
b0f  (Alan M)
www.b0f.net
_______________________________________________
UMR Security List Exploder
security () lists umr edu
https://lists.umr.edu/mailman/listinfo/security



-------------------------------------------------------
This sf.net email is sponsored by:ThinkGeek
Welcome to geek heaven.
http://thinkgeek.com/sf
_______________________________________________
cgiwrap-users mailing list
cgiwrap-users () lists sourceforge net
https://lists.sourceforge.net/lists/listinfo/cgiwrap-users



Current thread: