Bugtraq mailing list archives
Re: Regular Expression Denial of Service
From: Gadi Evron <ge () linuxbox org>
Date: Fri, 11 Sep 2009 19:21:24 +0300
Alex Roichman wrote:
Checkmarx Research Lab presents a new attack vector on Web applications. By exploiting the Regular Expression Denial of Service (ReDoS) vulnerability an attacker can make a Web application unavailable to its intended users. ReDoS is commonly known as a “bug” in systems, but Alex Roichman and Adar Weidman from Checkmarx show how serious it is and how using this technique, various applications can be “ReDoSed”. These include, among others, Server-side of Web applications and Client-side Browsers. The art of attacking the Web by ReDoS is by finding inputs which cannot be matched by Regexes and on these Regexes a Regex-based Web systems get stuck. For further reading: http://www.checkmarx.com/NewsDetails.aspx?id=23&cat=3
Alex, nice work. Thank you for sharing it with us.I'd recommend taking a look at Ilja van Sprundel's work with regular expression bugs in his Unusual bugs presentation. ... Where he played a bit with Google Code Search back in 2007, I think. He helped Google out by giving them his research, of course.
I found two versions online: http://www.ruxcon.org.au/files/2006/unusual_bugs.pdf http://www.slideshare.net/amiable_indian/unusual-bugsIlja and I later discussed creating a real regex fuzzer to discover vulnerabilities, but I at least never had the time to play with it. He might have, I am CC:ing him.
My best to Adar, Gadi Evron, http://www.gadievron.com/
Current thread:
- Regular Expression Denial of Service Alex Roichman (Sep 11)
- Re: Regular Expression Denial of Service Gadi Evron (Sep 11)
- Re[2]: Regular Expression Denial of Service Thierry Zoller (Sep 11)
- Re: Regular Expression Denial of Service Gadi Evron (Sep 11)
- Re: Re[2]: Regular Expression Denial of Service Jeffrey Walton (Sep 14)
- Re[2]: Regular Expression Denial of Service Thierry Zoller (Sep 11)
- Re: Regular Expression Denial of Service Pavel Kankovsky (Sep 14)
- Re: Regular Expression Denial of Service Pavel Kankovsky (Sep 14)
- <Possible follow-ups>
- Re: Regular Expression Denial of Service hackerwebzine (Sep 28)
- Re: Regular Expression Denial of Service Gadi Evron (Sep 11)