Due to an improper input validation, an unauthenticated threat actor can send a malicious message to a monitor thread within Rockwell Automation ThinServer™ and cause a denial-of-service condition on the affected device.
https://www.cisa.gov/news-events/ics-advisories/icsa-24-193-18
https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1677.html