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.

Kerio Personal Firewall (KPF) 2.1.4 and earlier allows remote attackers to execute administrator commands by sniffing packets from a valid session and replaying them against the remote administration server.

Buffer overflow in the administrator authentication process for Kerio Personal Firewall (KPF) 2.1.4 and earlier allows remote attackers to execute arbitrary code via a handshake packet.

Kerio Personal Firewall (KPF) 2.1.4 has a default rule to accept incoming packets from DNS (UDP port 53), which allows remote attackers to bypass the firewall filters via packets with a source port of 53.

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.

The Web Filtering functionality in Kerio Personal Firewall (KPF) 4.0.13 allows remote attackers to cause a denial of service (crash) by sending hex-encoded URLs containing "%13%12%13".

Kerio Personal Firewall (KPF) 2.1.4 and earlier allows remote attackers to cause a denial of service (hang and CPU consumption) via a SYN packet flood.

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 quickly obtain passwords that are 5 characters or less via brute force methods.

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 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."

kpf4ss.exe in Sunbelt Kerio Personal Firewall 4.3.x before 4.3.268 does not properly hook the CreateRemoteThread API function, which allows local users to cause a denial of service (crash) and bypass protection mechanisms by calling CreateRemoteThread.

Kerio Personal Firewall (KPF) 2.1.5 allows local users to execute arbitrary code with SYSTEM privileges via the Load button in the Firewall Configuration Files option, which does not drop privileges before opening the file loading dialog box.