Rockwell Automation MicroLogix 1100 PLC < FRN 10.0 Authentication Mechanism DoS

Critical Nessus Plugin ID 84570


The remote web server running on the MicroLogix 1100 PLC is affected by a denial of service vulnerability in the web server's password mechanism.


The Rockwell Automation MicroLogix 1100 PLC integrated web server is a firmware version that is prior to FRN 10.0. It is, therefore, affected by a denial of service vulnerability due to a failure of the authentication mechanism to properly handle remote connections or commands. A remote attacker can exploit this, using a crafted request, to cause the product to enter a predefined fault mode, resulting in the device being reset to a factory-default state.

Note that Nessus has not attempted to exploit this issue but has instead relied only on the self-reported version number.


Upgrade to MicroLogix 1100 PLC firmware release version FRN 10.0 or later.

See Also

Plugin Details

Severity: Critical

ID: 84570

File Name: scada_rockwell_micrologix_1100_plc_dos_278864.nbin

Version: $Revision: 1.24 $

Type: remote

Family: SCADA

Published: 2015/07/07

Modified: 2018/03/09

Dependencies: 84569

Risk Information

Risk Factor: Critical


Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Vulnerability Information

CPE: cpe:/a:rockwellautomation:micrologix:1100, cpe:/h:rockwellautomation:ab_micrologix_controller_1100

Required KB Items: SCADA/Rockwell Automation MicroLogix 1100 PLC Web Server

Patch Publication Date: 2011/05/17

Vulnerability Publication Date: 2011/05/17

Reference Information

CVE: CVE-2009-3739

BID: 37827

OSVDB: 61832, 61833