Unprivileged Certificate Bypass in IRONMACE Ironshield tvk.sys Driver

IRONMACE Ironshield 1.0.0.167 has a tvk.sys kernel-mode driver that authenticates client executables by checking for expected publisher and root-certificate strings in WIN_CERTIFICATE data ("IRONMACE Co., Ltd." and "DigiCert Trusted Root G4") instead of parsing and validating the PKCS signature data. As a result, a local unprivileged attacker may bypass this via crafted certificate data and obtain access to privileged IOCTL functionality.