---
title: "Attack: FRITZ!Box Security Bypass"
url: https://www.broadcom.com/support/security-center/attacksignatures/detail?asid=27399
description: Attack Signature Detail Page
---

# Attack: FRITZ!Box Security Bypass

## Severity: High

This attack could pose a serious security threat. You should take immediate action to stop any damage or prevent further damage from happening.

## Description

This signature detects attempts to exploit FRITZ!Box.

## Additional Information

FRITZ!Box is a wireless DSL modem and router. It is also configured for VoIP-telephony communications.

FRITZ!Box is prone to a remote denial-of-service vulnerability because the device fails to properly handle incoming UDP traffic. Specifically, a remote attacker can send a zero-length UDP packet to port 5060, the Session-Initiation-Protocol (SIP) of the device, through the IP interface or the DSL line. This will cause the VoIP-telephony service to crash, effectively denying service to legitimate users.

## Affected

- Multiple FRITZ!Box

## Additional Resources

- [SecurityFocus BID: 65520](http://www.securityfocus.com/bid/65520)