SCADA Vulnerabilities & Exposures (SVE)

CRITIFENCE® SCADA Vulnerabilities and Exposures Database (SVE)

[SVE-629091188] Rockwell Automation Allen-Bradley MicroLogix 1100 and 1400

Date Type Platform Author EDB-ID CVE-ID OSVDB-ID Download App SIS Signature
2017-05-23OtherRockwell AutomationThese vulnerabilities were reported to ICS-CERT by Rockwell Automation, David Formby and Raheem Beyah of Georgia Tech and FortipN/ACVE-2017-7901 CVE-2017-7902 CVE-2017-7899 CVE-2017-7898 CVE-2017N/AN/AN/A

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# Rockwell Automation Allen-Bradley MicroLogix 1100 and 1400
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### VULNERABLE VENDOR
Rockwell Automation


### VULNERABLE PRODUCT
Allen-Bradley MicroLogix 1100 and 1400



### RESEARCHER
These vulnerabilities were reported to ICS-CERT by Rockwell Automation, David Formby and Raheem Beyah of Georgia Tech and Fortiphyd Logic, Inc. Rockwell Automation also reported a vulnerability that was initially identified by Ilya Karpov of Positive Technologies.



### AFFECTED PRODUCTS

The following versions of the Allen-Bradley MicroLogix 1100 programmable-logic controller are affected:

1763-L16AWA, Series A and B, Version 16.00 and prior versions;
1763-L16BBB, Series A and B, Version 16.00 and prior versions;
1763-L16BWA, Series A and B, Version 16.00 and prior versions; and
1763-L16DWD, Series A and B, Version 16.00 and prior versions.
The following versions of the Allen-Bradley MicroLogix 1400 programmable logic controller are affected:

1766-L32AWA, Series A and B, Version 16.00 and prior versions;
1766-L32BWA, Series A and B, Version 16.00 and prior versions;
1766-L32BWAA, Series A and B, Version 16.00 and prior versions;
1766-L32BXB, Series A and B, Version 16.00 and prior versions;
1766-L32BXBA, Series A and B, Version 16.00 and prior versions; and
1766-L32AWAA, Series A and B, Version 16.00 and prior versions.



### IMPACT

Successful exploitation of these vulnerabilities may allow a remote attacker to gain unauthorized access to the affected programmable logic controllers and to spoof or disrupt TCP connections.



### VULNERABILITY OVERVIEW

PREDICTABLE VALUE RANGE FROM PREVIOUS VALUES CWE-343
Insufficiently random TCP initial sequence numbers are generated, which may allow an attacker to predict the numbers from previous values.
This may allow an attacker to spoof or disrupt TCP connections, resulting in a denial of service for the target device.
CVE-2017-7901 has been assigned to this vulnerability.
A CVSS v3 base score of 5.4 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L)


REUSING A NONCE, KEY PAIR IN ENCRYPTION CWE-323
The affected product reuses nonces, which may allow an attacker to capture and replay a valid request until the nonce is changed.
CVE-2017-7902 has been assigned to this vulnerability.
A CVSS v3 base score of 5.4 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L)


INFORMATION EXPOSURE CWE-200
User credentials are sent to the web server using the HTTP GET method, which may result in the credentials being logged.
This could make user credentials available for unauthorized retrieval.
CVE-2017-7899 has been assigned to this vulnerability.
A CVSS v3 base score of 3.1 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N)


IMPROPER RESTRICTION OF EXCESSIVE AUTHENTICATION ATTEMPTS CWE-307
There are no penalties for repeatedly entering incorrect passwords.
CVE-2017-7898 has been assigned to this vulnerability.
A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)


WEAK PASSWORD REQUIREMENTS CWE-521
The affected products use a numeric password with a small maximum character size for the password.
CVE-2017-7903 has been assigned to this vulnerability.
A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)





### BACKGROUND

Critical Infrastructure Sectors: Food and Agriculture, Water and Wastewater Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: Milwaukee, Wisconsin




### MITIGATION

Rockwell Automation has released a new firmware version for the Allen-Bradley MicroLogix 1400 Series B controllers, FRN 21.00, to address the identified vulnerabilities. Rockwell Automation encourages users to apply the latest firmware versions that address the identified vulnerabilities.

Rockwell Automation's new firmware version for the Allen-Bradley MicroLogix 1400 Series B controllers, FRN 21.00, is available at the following location:

http://compatibility.rockwellautomation.com/Pages/MultiProductDownload.aspx?Keyword=1766-Lxx&crumb=112


There are no firmware versions to address these vulnerabilities in the Allen-Bradley MicroLogix 1100 or MicroLogix 1400 Series A controllers, but Rockwell Automation has offered some compensating controls. Rockwell Automation reports that users can disable the web server on the Allen-Bradley MicroLogix 1100 and 1400 Series A controllers to protect against the exploitation of the improper restriction of excessive authentication attempts and weak password requirements vulnerabilities.

Rockwell Automation recommends that if it is not needed, users should consider disabling the web server to further mitigate these threats.

Disable the web server on the MicroLogix 1100 and 1400 controllers, if not needed, as it is enabled by default. See Knowledge Base article: 732398 for detailed instructions on disabling the web server. The Web Server Tech Note, KB: 732398 - How to Disable the Web Server in MicroLogix 1100 and 1400 is available at the following URL with a valid account:

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/732398


Set the mode to RUN via LCD soft keyswitch to prohibit any re-enabling of the web server while the keyswitch is in this mode.