CVE-2021-22659: rockwellautomation micrologix_1400_firmware Classic Buffer Overflow

Vulnerability summary

CVE-2021-22659 is a high (CVSS 8.6) Classic Buffer Overflow vulnerability in rockwellautomation micrologix_1400_firmware. EPSS estimates a 1.80% chance of exploitation in the next 30 days, higher than 78.2% of scored vulnerabilities.

Timeline

1. 25-03-2021
   PublishedVulnerability first disclosed.
2. 03-06-2026
   Last modifiedVulnerability information updated.

Description

Rockwell Automation MicroLogix 1400 Version 21.6 and below may allow a remote unauthenticated attacker to send a specially crafted Modbus packet allowing the attacker to retrieve or modify random values in the register. If successfully exploited, this may lead to a buffer overflow resulting in a denial-of-service condition. The FAULT LED will flash RED and communications may be lost. Recovery from denial-of-service condition requires the fault to be cleared by the user.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.