A denial of service vulnerability exists in Wibu-Systems CodeMeter versions < 7.21a. An unauthenticated remote attacker can exploit this issue to crash the CodeMeter Runtime Server.
https://www.tenable.com/security/research/tra-2021-24
https://us-cert.cisa.gov/ics/advisories/icsa-21-210-02
https://cert-portal.siemens.com/productcert/pdf/ssa-675303.pdf
https://cdn.wibu.com/fileadmin/wibu_downloads/security_advisories/Advisory_WIBU-210423-02.pdf