CVE-2020-22552
The Snap7 server component in version 1.4.1, when an attacker sends a crafted packet with COTP protocol the last-data-unit flag set to No and S7 writes a var function, the Snap7 server will be crashed.
Date published : 2020-10-28
https://sourceforge.net/p/snap7/discussion/bugfix/thread/456d76fdde/