Bugtraq mailing list archives
Re: Regular Expression Denial of Service
From: Gadi Evron <ge () linuxbox org>
Date: Sat, 12 Sep 2009 00:10:08 +0300
Thierry Zoller wrote:
Hi , With all due respect - this is known to be a vulnerability class since over a century. Just because it doesn't have a acronym à la XSS doesn't mean it's not known to be a vulnerability. Can we please stop the attitude of inventing acronyms for vulnerabilites, making it look like it's something new and funky. It's the impact of something that makes it a vulnerability no the name.
Thierry, you are quite right. However, I don't think they claimed it was a new class of vulnerabilities, and the responses since just added data to it. So I think that while you are factually correct, you misread their post. They shared their research with us.
Gadi.
GE> 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=3GE> Alex, nice work. Thank you for sharing it with us.GE> I'd recommend taking a look at Ilja van Sprundel's work with regular GE> expression bugs in his Unusual bugs presentation.GE> ... Where he played a bit with Google Code Search back in 2007, I think. GE> He helped Google out by giving them his research, of course. GE> I found two versions online: GE> http://www.ruxcon.org.au/files/2006/unusual_bugs.pdf GE> http://www.slideshare.net/amiable_indian/unusual-bugsGE> Ilja and I later discussed creating a real regex fuzzer to discover GE> vulnerabilities, but I at least never had the time to play with it. HeGE> might have, I am CC:ing him. GE> My best to Adar, GE> Gadi Evron, GE> 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)