The x11_open_helper function in channels.c in ssh in OpenSSH before 6.9, when ForwardX11Trusted mode is not used, lacks a check of the refusal deadline for X connections, which makes it easier for remote attackers to bypass intended access restrictions via a connection outside of the permitted time window.
Exploitability
AV:NAC:MAu:NImpact
C:NI:PA:N4.3/AV:N/AC:M/Au:N/C:N/I:P/A:N