CVE-2004-1109

Kerio Personal Firewall <= 4.1.1 - Denial of Service via Zero-Length IP Option Field

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2004-1109. PoCs published by houseofdabus.

AI-analyzed exploit summary This is a proof-of-concept exploit for CVE-2004-1109, targeting Kerio Personal Firewall 4.1.1 and prior. It crafts a malformed UDP packet with multiple IP options to trigger a denial-of-service condition, causing the system to freeze.

Description

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.

Exploits (1)

exploitdb WORKING POC VERIFIED
by houseofdabus · cdoswindows
https://www.exploit-db.com/exploits/626

This is a proof-of-concept exploit for CVE-2004-1109, targeting Kerio Personal Firewall 4.1.1 and prior. It crafts a malformed UDP packet with multiple IP options to trigger a denial-of-service condition, causing the system to freeze.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Kerio Personal Firewall 4.1.1 and prior
No auth needed
Prerequisites: Network access to the target system · Ability to send raw packets
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_xf
https://exchange.xforce.ibmcloud.com/vulnerabilities/17992
Vendor Advisory x_refsource_confirm
http://www.kerio.com/security_advisory.html
Exploit, Patch, Vendor Advisory vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/11639
Various Sources third-party-advisory x_refsource_eeye
http://www.eeye.com/html/research/advisories/AD20041109.html

Scores

EPSS 0.0324
EPSS Percentile 86.7%

Details

Status published
Products (8)
kerio/personal_firewall 4.0.6
kerio/personal_firewall 4.0.7
kerio/personal_firewall 4.0.8
kerio/personal_firewall 4.0.9
kerio/personal_firewall 4.0.10
kerio/personal_firewall 4.0.16
kerio/personal_firewall 4.1
kerio/personal_firewall 4.1.1
Published Jan 10, 2005
Tracked Since Feb 18, 2026