A vulnerability related to the use an insecure Platform Key (PK) has been discovered. An attacker with the compromised PK private key can create malicious UEFI software that is signed with a trusted key that has been compromised.

xrdb.c in xrdb before 1.0.9 in X.Org X11R7.6 and earlier allows remote attackers to execute arbitrary commands via shell metacharacters in a hostname obtained from a (1) DHCP or (2) XDMCP message.