State of knowledge

13 December 2021

The German Federal Office for Information Security has declared IT Threat Level 4/Red for the CVE-2021-44228 ("log4shell") vulnerability in the widely used Java software library log4j.

estos products are not affected by this vulnerability and can continue to be used without modification and without hesitation.

estos software is not based on Java and is therefore generally not affected by Java-related vulnerabilities. The only exception is ProCall for Android, here Java is partly used, but not log4j (neither version 1 nor 2).

Supplementary notes

  • log4javascript.js ( is a different technology that has nothing to do with log4j. Currently used in ProCall Analytics, for example.
  • Apache log4net ( to be confused with Apache web server, Apache Tomcat or other Apache projects) is a different technology. There was security advice for this, for which we have provided new software versions.