Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

7/17/2012
05:45 PM
50%
50%

Will Advanced Attackers Laugh At Your WAF?

Companies should not trust vendors' claims about Web application firewalls, says security engineer who at Black Hat USA will show 150 different ways attackers can get around Web defenses

Companies worried about their Web security cannot just deploy a Web application firewall (WAF) in front of their sites and call it a day. Using a variety of tricks -- including, in a few cases, just adding a single character -- a knowledgeable attacker could bypass the additional security offered by WAFs, according to research that will be presented at the Black Hat USA security conference next week.

   
Click here for more of Dark Reading's Black Hat articles.

From the simple handling of file names and path names, to more complex multipart and unicode parsing, different Web servers and security software handle the HTTP protocol in different ways. By exploiting the disconnect between a Web server and its WAF, an attacker could bypass defenses to exploit vulnerabilities in a Web server, says Ivan Ristic, director of engineering for vulnerability management firm Qualys, who will present his research at Black Hat.

"This is about attacking the way that a Web application firewall interprets data streams," says Ristic, who has developed WAFs for more than a decade, including the creation of the open-source WAF ModSecurity. "There has not been a good public discussion and disclosure of these issues, aside for the occasional vulnerability."

While there has not been a large number of attackers that have used evasion techniques to date, the increasing use of WAFs means that attackers will have to adapt and find ways around them. To help improve the ability of customers and penetration testers to gauge the security of WAFs, Ristic plans to release a set of nearly 150 tests for a variety of security weaknesses that he had identified in current WAFs.

Being able to test a vendor's product before deploying it could help immensely, says Paul Sop, technology evangelist for attack-mitigation firm Prolexic. His company tested a handful of systems and had little trouble bypassing all of them. For most companies, however, that level of evaluation will be out of their capabilities.

"There are many, many different attack vectors, and you have to kind of somehow know which attack vector maps to which features and how do you test it," he says. "How do you certify and prove that this control that you just activated actually works?"

[ Two researchers release a hacking tool called Waldo to test for WebSocket vulnerabilities and potential attack vectors, which will be demonstrated at Black Hat USA. See 'Waldo' Finds Ways To Abuse HTML5 WebSockets. ]

A strong set of tests could help customers check on vendors' claims and help vendors improve their systems, he says. In addition, many companies only turn on the features necessary to be PCI-compliant rather than tuning the WAF to their environment.

"To turn on a certain abstract feature of a WAF, you have to know a lot about the HTTP protocol and the application that you are protecting," Sop says. "If you don't turn on a protection for something, then it's not going to do anything."

Luckily, the run-of-the-mill attacker will likely not be dodging their target's WAF any time soon, says Qualys' Ristic. Designing evasions for WAFs requires a lot of knowledge about the systems, he says.

"These are advanced attacks, so the obvious attackers won't use them," he says. "Developing these types of attacks takes a lot of dedication. I would expect these evasion techniques to be used when a high-value target is involved."

The security technologies add an extra layer of security in front of a public website catching attacks against vulnerabilities that developers may have missed or that have gone unpatched. Overall, WAFs are a good security technology, but need a great deal more research, Ristic argues. In addition, vendors need to be more transparent regarding their technologies and products, he says.

"Users, in general, should make it clear to the vendors that they care about the quality in WAFs," he says. "I have been involved in WAF development for 10 years, but I'm disappointed by the current state of the market."

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 9/21/2020
Hacking Yourself: Marie Moe and Pacemaker Security
Gary McGraw Ph.D., Co-founder Berryville Institute of Machine Learning,  9/21/2020
Startup Aims to Map and Track All the IT and Security Things
Kelly Jackson Higgins, Executive Editor at Dark Reading,  9/22/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Special Report: Computing's New Normal
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
How IT Security Organizations are Attacking the Cybersecurity Problem
How IT Security Organizations are Attacking the Cybersecurity Problem
The COVID-19 pandemic turned the world -- and enterprise computing -- on end. Here's a look at how cybersecurity teams are retrenching their defense strategies, rebuilding their teams, and selecting new technologies to stop the oncoming rise of online attacks.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-15222
PUBLISHED: 2020-09-24
In ORY Fosite (the security first OAuth2 & OpenID Connect framework for Go) before version 0.31.0, when using "private_key_jwt" authentication the uniqueness of the `jti` value is not checked. When using client authentication method "private_key_jwt", OpenId specification say...
CVE-2020-15223
PUBLISHED: 2020-09-24
In ORY Fosite (the security first OAuth2 & OpenID Connect framework for Go) before version 0.34.0, the `TokenRevocationHandler` ignores errors coming from the storage. This can lead to unexpected 200 status codes indicating successful revocation while the token is still valid. Whether an attacke...
CVE-2020-12842
PUBLISHED: 2020-09-24
ismartgate PRO 1.5.9 is vulnerable to privilege escalation by appending PHP code to /cron/checkUserExpirationDate.php.
CVE-2020-12843
PUBLISHED: 2020-09-24
ismartgate PRO 1.5.9 is vulnerable to malicious file uploads via the form for uploading sounds to garage doors. The magic bytes for WAV must be used.
CVE-2020-13119
PUBLISHED: 2020-09-24
ismartgate PRO 1.5.9 is vulnerable to clickjacking.