OpenWrt Router with a Blank Password (telnet check) - Nessus

Critical   Plugin ID: 40354

This page contains detailed information about the OpenWrt Router with a Blank Password (telnet check) 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

ID: 40354
Name: OpenWrt Router with a Blank Password (telnet check)
Filename: openwrt_blank_telnet_password.nasl
Vulnerability Published: N/A
This Plugin Published: 2009-07-23
Last Modification Time: 2021-01-19
Plugin Version: 1.9
Plugin Type: remote
Plugin Family: CGI abuses
Dependencies: telnetserver_detect_type_nd_version.nasl

Vulnerability Information

Severity: Critical
Vulnerability Published: N/A
Patch Published: N/A
CVE [?]: CVE-1999-0508
CPE [?]: N/A

Synopsis

The remote router does not have a password set.

Description

The remote host is running OpenWrt, an open source Linux distribution for embedded devices, especially routers.

It is currently configured without a password, which is the case by default. Anyone can connect to the device via Telnet and gain administrative access to it.

Solution

Set a password for the device.

Public Exploits

Target Network Port(s): 23
Target Asset(s): Services/telnet
Exploit Available: True (Metasploit Framework)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the OpenWrt Router with a Blank Password (telnet check) vulnerability:

  1. Metasploit: auxiliary/scanner/snmp/snmp_login
    [SNMP Community Scanner]
  2. Metasploit: auxiliary/scanner/snmp/snmp_login
    [SNMP Community Login Scanner]

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.

Risk Information

CVSS V2 Vector [?]: AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Base Score:10.0 (High)
Impact Subscore:10.0
Exploitability Subscore:10.0
CVSS Temporal Score:NA (None)
CVSS Environmental Score:NA (None)
Modified Impact Subscore:NA
Overall CVSS Score:10.0 (High)

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Plugin Source

This is the openwrt_blank_telnet_password.nasl nessus plugin source code. This script is Copyright (C) 2009-2021 Tenable Network Security, Inc. 

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


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


if (description)
{
  script_id(40354);
  script_version("1.9");

  script_cve_id("CVE-1999-0508");

  script_name(english:"OpenWrt Router with a Blank Password (telnet check)");
  script_summary(english:"Tries to access OpenWrt without a password");

  script_set_attribute(
    attribute:"synopsis",
    value:"The remote router does not have a password set."
  );
  script_set_attribute( attribute:"description",  value:
"The remote host is running OpenWrt, an open source Linux distribution
for embedded devices, especially routers. 

It is currently configured without a password, which is the case by
default.  Anyone can connect to the device via Telnet and gain
administrative access to it."  );
  script_set_attribute(
    attribute:"see_also", 
    value:"http://oldwiki.openwrt.org/OpenWrtDocs%282f%29Using.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Set a password for the device."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'SNMP Community Scanner');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
  script_set_attribute(
    attribute:"plugin_publication_date", 
    value:"2009/07/23"
  );
 script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/19");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2009-2021 Tenable Network Security, Inc.");

  script_dependencies("telnetserver_detect_type_nd_version.nasl");
  script_require_ports("Services/telnet", 23);

  exit(0);
}


include("global_settings.inc");
include("telnet_func.inc");


port = get_kb_item("Services/telnet");
if (!port) port = 23;
if (!get_tcp_port_state(port)) exit(0, "No Telnet service was detected.");


banner = get_telnet_banner(port:port);
if (
  banner &&
  "Use 'passwd' to set your login password" >< banner &&
  "W I R E L E S S   F R E E D O M" >< banner &&
  "root@" >< banner
)
{
  # Unless we're paranoid, make sure it's really OpenWrt.
  if (report_paranoia < 2)
  {
    soc = open_sock_tcp(port);
    if (soc)
    {
      res = telnet_negotiate(socket:soc);
      res += recv_until(socket:soc, pattern:"root@");
      if (!res)
      {
        close(soc);
        exit(0, "Didn't receive a command prompt.");
      }
      send(socket:soc, data:'cat /proc/version\r\n');

      res = recv_until(socket:soc, pattern:"OpenWrt");
      if (!res)
      {
        close(soc);
        exit(0, "'/proc/version' doesn't mention OpenWrt.");
      }
      close(soc);
    }
    else exit(1, "Can't open a socket to verify it's really OpenWrt.");
  }

  set_kb_item(name:"openwrt/blank_telnet_password", value:TRUE);

  if (report_verbosity > 0)
  {
    report = string(
      "\n",
      "The remote device uses the following banner :\n",
      "\n",
      crap(data:"-", length:30), " snip ", crap(data:"-", length:30), "\n",
      banner, "\n",
      crap(data:"-", length:30), " snip ", crap(data:"-", length:30), "\n"
    );
    security_hole(port:port, extra:report);
  }
  else security_hole(port);

  exit(0);
}
exit(0, "The host is not affected.");

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

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

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How to Run

Here is how to run the OpenWrt Router with a Blank Password (telnet check) as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

  1. Click to start a New Scan.
  2. Select Advanced Scan.
  3. Navigate to the Plugins tab.
  4. On the top right corner click to Disable All plugins.
  5. On the left side table select CGI abuses plugin family.
  6. On the right side table select OpenWrt Router with a Blank Password (telnet check) plugin ID 40354.
  7. Specify the target on the Settings tab and click to Save the scan.
  8. 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 openwrt_blank_telnet_password.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

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

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

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

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References

See also: Similar and related Nessus plugins:
  • 10747 - 3Com Superstack 3 Switch Multiple Default Accounts
  • 18415 - Bay Networks Accelar 1200 Switch Default Password (password) for 'usrname' Account
  • 18414 - Allied Telesyn Router/Switch Default Password
  • 18413 - Allied Telesyn Router/Switch Web Interface Default Password
  • 17638 - Avaya P330 Stackable Switch Default Password
  • 10961 - AirConnect Default Password
  • 11202 - Enhydra Multiserver Default Password
  • 10820 - F5 Device Default Support Password
  • 10995 - Sun JavaServer Default Admin Password
  • 10998 - Shiva LanRover Blank Password
  • 10999 - Linksys Router Default Password
  • 11203 - Motorola Vanguard with No Password (telnet check)
  • 10798 - Symantec pcAnywhere Service Unrestricted Access
  • 10778 - SiteScope Web Service Unpassworded Access
  • 11004 - Ipswitch WhatsUp Gold Default Admin Account
  • 30213 - MikroTik RouterOS with Blank Password (telnet check)
  • 10345 - Cayman DSL Router Unauthenticated Access
  • 10483 - PostgreSQL Default Unpassworded Account
  • 10500 - Shiva Integrator Default Password
  • 10827 - SysV /bin/login Environment Remote Overflow (telnet check)

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file openwrt_blank_telnet_password.nasl version 1.9. For more plugins, visit the Nessus Plugin Library.

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