Rockwell Plan to Fix Cisco Holes

Thursday, August 24, 2017 @ 01:08 PM gHale


Rockwell Automation has a strategy plan in place to mitigate SNMP remote code execution vulnerabilities in Cisco IOS and IOS XE Software in its Allen-Bradley Stratix and ArmoStratix products, according to a report with ICS-CERT.

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

RELATED STORIES
ALC Mitigation Plan for Product Holes
SpiderControl Fixes SCADA Web Server
SpiderControl MicroBrowser Fixed
Marel Updates Food Processing Systems

The following versions of Allen-Bradley Stratix and ArmorStratix switches suffer from the issue:
• 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

Multiple Cisco vulnerabilities in the Simple Network Management Protocol (SNMP) subsystem of Cisco IO and IOS XE software ended up identified which affect certain products in the Allen-Bradley Stratix and ArmorStratix product lines.

For more information about the SNMP vulnerabilities identified by Cisco, click here to see their advisory.

No known public exploits specifically target this vulnerability. However, an attacker with low skill level would be able to leverage the issues.

Cisco 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 are the case numbers assigned to these vulnerabilities, which have a CVSS v3 base score of 8.8.

These products see action in the critical manufacturing, energy, and water and wastewater systems sectors. They also see use on a global basis.

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.

Milwaukee, WI-based 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.

o 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

Click here for details on how to use the command line interface to disable or limit access to SNMP or individual MIBs through Rockwell’s . Knowledgebase Article ID 1055391. A login is required to view the article.

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

1. If SNMP is required, use strong SNMP v3 credentials since this attack requires authentication.
2. Cisco Talos, Cisco’s 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.”
3. 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 release to remediate this vulnerability, Rockwell Automation will provide mitigation updates in their advisory. For more information about these vulnerabilities, mitigation updates, and Rockwell Automation’s general security guidelines, please see Rockwell Automation’s security advisory. A login is required to view the advisory.



Leave a Reply

You must be logged in to post a comment.