An exploitable stack buffer overflow vulnerability vulnerability exists in the iocheckd service ‘I/O-Check’ functionality of WAGO PFC 200 Firmware version 03.02.02(14). The destination buffer sp+0x440 is overflowed with the call to sprintf() for any domainname values that are greater than 1024-len(‘/etc/config-tools/edit_dns_server domain-name=‘) in length. A domainname value of length 0x3fa will cause the service to crash.