PT-2021-20019 · Rockwell Automation · Micrologix 1100

Beau Taub · Published 2021-07-09 · Updated 2021-07-12 · CVE-2021-33012

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Rockwell Automation MicroLogix 1100, all versions

Description The issue allows a remote, unauthenticated attacker to send specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, resulting in a denial-of-service condition. If successfully exploited, this will cause the controller to fault whenever the controller is switched to RUN mode.

Recommendations For Rockwell Automation MicroLogix 1100, all versions, consider temporarily restricting access to the controller when switching to RUN mode until a patch is available. As a mitigation measure, restrict the ability to send specially crafted commands to the PLC to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2021-33012

Affected Products

Micrologix 1100

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2021-33012 · Security Note
• https://us-cert.cisa.gov/ics/advisories/icsa-21-189-01 · Note
• https://t.me/cvenotify/17480 · Telegram Post