Microsoft IIS 5.0 - WebDAV Lock Method Memory Leak Denial of Service

Author: Defcom Labs
type: dos
platform: windows
port: 0
date_added: 2001-05-17
date_updated: 2016-12-14
verified: 1
codes: OSVDB-52680
tags: 
aliases: 
screenshot_url: 
application_url: 

source: https://www.securityfocus.com/bid/2736/info

Microsoft IIS 5.0 is vulnerable to a denial of service attack.

A flaw in the WebDav extensions allow a remote attacker to carry out a DoS by repeatedly requesting nonexistent files via the HTTP LOCK method.

This leads to a complete consumption of memory resources, eventually crashing the host and requiring a restart.

LOCK /aaaaaaaaaaaaaaaaaaaaaaaaaa.htw HTTP/1.0

One way is to combine the attack with asp executions, eg.

GET /iisstart.asp?uc=a HTTP/1.0