CVE-2019-9590 February 26, 2023 by An issue was discovered on TENGCONTROL T-920 PLC v5.5 devices. It allows remote attackers to cause a denial of service (persistent failure mode) by sending a series of x19xb2x00x00x00x06x43x01x00xacxffx00 (aka UID 0x43) requests to TCP port 502.