The FWDRV driver in Kerio Personal Firewall 4.2 and Server Firewall 1.1.1 allows local users to cause a denial of service (crash) by setting the PAGE_NOACCESS or PAGE_GUARD protection on the Page Environment Block (PEB), which triggers an exception, aka the "PEB lockout vulnerability."
Exploitability
AV:LAC:LAu:NImpact
C:NI:NA:P2.1/AV:L/AC:L/Au:N/C:N/I:N/A:P