ESB-2017.2136 - [Appliance] Allen-Bradley Stratix and ArmorStratix: Multiple vulnerabilities 2017-08-25

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.2136
        Advisory (ICSA-17-208-04) Rockwell Automation Allen-Bradley
                          Stratix and ArmoStratix
                              25 August 2017

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Allen-Bradley Stratix
                   Allen-Bradley ArmorStratix
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Root Compromise   -- Existing Account
                   Denial of Service -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-6744 CVE-2017-6743 CVE-2017-6742
                   CVE-2017-6741 CVE-2017-6740 CVE-2017-6739
                   CVE-2017-6738 CVE-2017-6737 CVE-2017-6736

Reference:         ESB-2017.1737
                   ESB-2017.1644.2

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-17-208-04

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Advisory (ICSA-17-208-04)

Rockwell Automation Allen-Bradley Stratix and ArmoStratix

Original release date: August 24, 2017

Legal Notice

All information products included in http://ics-cert.us-cert.gov are provided
"as is" for informational purposes only. The Department of Homeland Security 
(DHS) does not provide any warranties of any kind regarding any information 
contained within. DHS does not endorse any commercial product or service, 
referenced in this product or otherwise. Further dissemination of this product
is governed by the Traffic Light Protocol (TLP) marking in the header. For 
more information about TLP, see http://www.us-cert.gov/tlp/.

CVSS v3 8.8

ATTENTION: Remotely exploitable/low skill level to exploit

Vendor: Rockwell Automation

Equipment: Allen-Bradley Stratix and ArmoStratix

Vulnerabilities: SNMP Remote Code Execution Vulnerabilities in Cisco IOS and 
IOS XE Software

REPOSTED INFORMATION

This advisory was originally posted to the NCCIC Portal on July 27, 2017, and
is being released to the NCCIC/ICS-CERT web site.

AFFECTED PRODUCTS

The following versions of Allen-Bradley Stratix and ArmorStratix switches are
affected:

All Versions 15.2(5)EA.fc4 and earlier

Allen-Bradley Stratix 5400 Industrial Ethernet Switches

Allen-Bradley Stratix 5410 Industrial Distribution Switches

Allen-Bradley Stratix 5700 and ArmorStratix 5700 Industrial Managed Ethernet 
Switches

Allen-Bradley Stratix 8000 Modular Managed Ethernet Switches

All Versions 15.6(3)M1 and earlier

Allen-Bradley Stratix 5900 Services Router

All Versions 15.2(4)EA and earlier

Stratix 8300 Modular Managed Ethernet Switches

IMPACT

Successful exploitation of these vulnerabilities could allow an authenticated,
remote attacker to execute code on an affected system or cause an affected 
system to crash and reload.

MITIGATION

According to Rockwell Automation, multiple Cisco Systems, Inc. vulnerabilities
in the Simple Network Management Protocol (SNMP) subsystem of Cisco IO and IOS
XE software have been identified which affect certain products in the 
Allen-Bradley Stratix and ArmorStratix product lines.

For more information about the SNMP vulnerabilities identified by Cisco, see 
their advisory at the link below:

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
(link is external)

Rockwell Automation recommends users of affected products consult the 
suggestions below and, when possible, employ multiple strategies to mitigate 
their risk:

For the Stratix 8300 Product Family, Catalog Numbers 1783-RMS, Rockwell 
Automation suggests updating to v15.2(4a)EA5 or later. This can be found at 
the following link:

https://compatibility.rockwellautomation.com/Pages/MultiProductDownload.aspx?famID=15
(link is external)

Rockwell Automation has provided interim compensating controls for the 
remaining Allen-Bradley Stratix and ArmorStratix switches to help reduce the 
risk of exploitation of these vulnerabilities. Rockwell Automation encourages
users to evaluate the compensating controls provided below and apply the 
possible mitigations.

Disable the following Management Information Bases (MIBs) on a device, if they
are installed/active on the Stratix device:

Stratix 8000, 8300, 5700, 5400, 5410

CISCO-MAC-AUTH-BYPASS-MIB

Stratix 5900

ADSL-LINE-MIB

CISCO-ADSL-DMT-LINE-MIB

CISCO-BSTUN-MIB

CISCO-MAC-AUTH-BYPASS-MIB

CISCO-VOICE-DNIS-MIB

Details on how to use the Command Line Interface to disable or limit access to
SNMP or individual MIBs can be found at Knowledgebase Article ID 1055391 (link
is external). A login is required to view the article.

Note: The Stratix device may not have all of the MIBs installed/active.

If SNMP is required, use strong SNMP v3 credentials since this attack requires
authentication.

Cisco Talos, Ciscos threat intelligence organization, has created the 
following Snort rules (SIDs): 43424, 43425, 43426, 43427, 43428, 43429, 43430,
43431, 43432 to detect exploits utilizing this vulnerability, which can be 
used on Stratix 5950 Security Appliances positioned appropriately within the 
network architecture to provide enhanced visibility. The Snort rules (SIDs) 
are enabled following curated rule sets Balanced Security and Connectivity, 
Connectivity over Security, and Secure over Connectivity.

Use proper network infrastructure controls, such as firewalls, to help ensure
that SNMP requests from unauthorized sources are blocked. Firewalls will not 
block requests from compromised but authorized sources.

As new versions of firmware are released to remediate this vulnerability, 
Rockwell Automation will provide mitigation updates in their advisory. For 
more information about these vulnerabilities, mitigation updates, and Rockwell
Automations general security guidelines, please see Rockwell Automations 
security advisory found at the following link. A login is required to view the
advisory.

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1055133 (link
is external)

ICS-CERT recommends that users take defensive measures to minimize the risk of
exploitation of these vulnerabilities. Specifically, users should:

Minimize network exposure for all control system devices and/or systems, and 
ensure that they are not accessible from the Internet.

Locate control system networks and remote devices behind firewalls, and 
isolate them from the business network.

When remote access is required, use secure methods, such as Virtual Private 
Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be
updated to the most current version available. Also recognize that VPN is only
as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk 
assessment prior to deploying defensive measures.

ICS-CERT also provides a section for control systems security recommended 
practices on the ICS-CERT web page. Several recommended practices are 
available for reading and download, including Improving Industrial Control 
Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly 
available in the ICSCERT Technical Information Paper, 
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation 
Strategies, that is available for download from the ICS-CERT web site.

Organizations observing any suspected malicious activity should follow their 
established internal procedures and report their findings to ICS-CERT for 
tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.

VULNERABILITY OVERVIEW

SNMP REMOTE CODE EXECUTION VULNERABILITIES CWE-119 (link is external)

Cisco Systems, Inc. has identified multiple SNMP remote code execution 
vulnerabilities in Cisco IOS and IOS XE Software affecting version of 
Allen-Bradley Stratix and ArmorStratix. To exploit these vulnerabilities via 
SNMP v2c or earlier, attacker must know the SNMP read-only community string 
for the affected system. To exploit these vulnerabilities in SNMP v3, an 
attacker must authenticate with user credentials. If exploited, this could 
allow a remote attacker to execute arbitrary code on the affected Stratix and
ArmorStratix system.

CVE-2017-6736, CVE-2017-6737, CVE-2017-6738, CVE-2017-6739, CVE-2017-6740, 
CVE-2017-6741, CVE-2017-6742, CVE-2017-6743 and CVE-2017-6744 have been 
assigned to these vulnerabilities. A CVSS v3 base score of 8.8 has been 
assigned; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

RESEARCHER

Cisco discovered these vulnerabilities during internal testing. Rockwell 
Automation reported these vulnerabilities to ICS-CERT.

BACKGROUND

Critical Infrastructure Sectors: Critical Manufacturing, Energy, and Water and
Wastewater Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Milwaukee, Wisconsin

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: ics-cert@hq.dhs.gov (link sends e-mail)

Toll Free: 1-877-776-7585

International Callers: (208) 526-0900

For industrial control systems security information and incident reporting: 
http://ics-cert.us-cert.gov

ICS-CERT continuously strives to improve its products and services. You can 
help by choosing one of the links below to provide feedback about this 
product.

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