CVE-2019-5172 — OS Command Injection in Pfc200

An exploitable command injection vulnerability exists in the iocheckd service ‘I/O-Check’ function of the WAGO PFC 200 Firmware version 03.02.02(14). An attacker can send a specially crafted packet to trigger the parsing of this cache file. At 0x1e840 the extracted ntp value from the xml file is used as an argument to /etc/config-tools/config_sntp time-server-%d= 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 ntp e…