The (1) fwdrv.sys and (2) khips.sys drivers in Sunbelt Kerio Personal Firewall 4.3.268 and earlier do not validate arguments passed through to SSDT functions, including NtCreateFile, NtDeleteFile, NtLoadDriver, NtMapViewOfSection, NtOpenFile, and NtSetInformationFile, which allows local users to cause a denial of service (crash) and possibly other impacts via unspecified vectors.

Unknown vulnerability in Kerio Personal Firewall 4.1.2 and earlier allows local users to bypass firewall rules via a malicious process that impersonates a legitimate process that has fewer restrictions.

The administration protocol for Kerio WinRoute Firewall 6.x up to 6.0.10, Personal Firewall 4.x up to 4.1.2, and MailServer up to 6.0.8 allows remote attackers to cause a denial of service (CPU consumption) via certain attacks that force the product to "compute unexpected conditions" and "perform cryptographic operations."

The FWDRV.SYS driver in Kerio Personal Firewall 4.1.1 and earlier allows remote attackers to cause a denial of service (CPU consumption and system freeze from infinite loop) via a (1) TCP, (2) UDP, or (3) ICMP packet with a zero length IP Option field.

Kerio Personal Firewall 4.0 (KPF4) allows local users with administrative privileges to bypass the Application Security feature and execute arbitrary processes by directly writing to \device\physicalmemory to restore the running kernel's SDT ServiceTable.