FAUST iServer before 9.0.019.019.7 is susceptible to local file inclusion because for each URL request it accesses the corresponding .fau file on the operating system without preventing %2e%2e%5c directory traversal.
View the template here CVE-2021-34805.yaml
References:
http://www.land-software.de/lfs.fau?prj=iweb&dn=faust+iserver