An exploitable command injection vulnerability exists in the iocheckd service ‘I/O-Check’ function of the WAGO PFC 200 version 03.02.02(14). At 0x1e3f0 the extracted dns value from the xml file is used as an argument to /etc/config-tools/edit_dns_server %s dns-server-nr=%d dns-server-name=<contents of dns node> using sprintf(). This command is later executed via a call to system(). This is done in a loop and there is no limit to how many dns entries will be parsed from the xml file.