homepage Welcome to WebmasterWorld Guest from
register, free tools, login, search, pro membership, help, library, announcements, recent posts, open posts,
Become a Pro Member
Home / Forums Index / Code, Content, and Presentation / XML Development
Forum Library, Charter, Moderators: httpwebwitch

XML Development Forum

XML bomb resurfaces

WebmasterWorld Administrator httpwebwitch us a WebmasterWorld Top Contributor of All Time 10+ Year Member

Msg#: 3986067 posted 4:17 pm on Sep 8, 2009 (gmt 0)

In the XML world, there was a famous vulnerability discovered by Amit Klein back in 2002 which used recursion in DTD's (Document Type Definitions) in order to create a Denial-of-Service attack on an XML parser. The attack involved a cleverly crafted DTD which was designed to expand greatly in memory when parsed, using recursion, earning it the name "XML Bomb".
source [soa.sys-con.com]

The bomb was discovered, then defused by a couple of patches issued by IBM and Microsoft. So, problem solved, right?

it cropped up again last week ...[snip]...Vulnerabilities discovered in XML libraries from Sun, Apache Software Foundation, Python Software Foundation and the GNOME Project could result in successful denial-of-service attacks on applications built with them. ...[snip]... Some XML libraries are still naively consuming DTDs and falling victim to recursion attacks.
(same source)

The vulnerability surfaces in situations where your app accepts and parses XML without blocking inline DTDs. For example, a request to a SOAP web service, or an API that accepts XML as an input parameter.


Global Options:
 top home search open messages active posts  

Home / Forums Index / Code, Content, and Presentation / XML Development
rss feed

All trademarks and copyrights held by respective owners. Member comments are owned by the poster.
Home ¦ Free Tools ¦ Terms of Service ¦ Privacy Policy ¦ Report Problem ¦ About ¦ Library ¦ Newsletter
WebmasterWorld is a Developer Shed Community owned by Jim Boykin.
© Webmaster World 1996-2014 all rights reserved