Google's virtual Chrome army attacks web applications to find bugs

Google has launched a vulnerability scanner that only targets two web application flaws by hammering them in a multi-stage attack. While it misses many bugs, the result for developers may be cheaper manual security reviews.

Vulnerability scanners aren’t new, but Google says it’s Cloud Security Scanner is a little different than others. First, the new beta service will miss many of OWASP’s top 10 web application vulnerabilities and it’s designed to do so. It’s also got an emphasis on avoiding false-positives, so may gloss over possible flaws. But that’s exactly what it's meant to do since it is aimed at finding as many of the most common flaws in a web application as possible in the least amount of time.

The only two bugs it targets are cross-site scripting (XXS) flaws and mixed content scripts, which Google argues are the most common App Engine developers face.

“It crawls your application, following all links within the scope of your starting URLs, and attempts to exercise as many user inputs and event handlers as possible,” Google explains.

The new service comes with numerous caveats. The scan may miss sections of an application and Google also warns its actions“may lead to undesirable results”. For example, it may trigger a large number of test emails in an email sign-up page or start posting test strings as comments on a blog application that allows public comments.

Also, the service only supports App Engine instances but not App Engine managed virtual machines, Google Compute Engine or other resources.

But the chief design goals for the scanner were to create an easy to use tool that detects the most common web flaws, as well as support the scanning of HTML5, JavaScript-heavy web applications.

Rob Mann, a Google security engineering manager explained that the scanner cherry picks the best features from using an emulated browser, which is fast but misses certain actions, versus using a real browser, which is slow but more comprehensive.

The answer lies in a probe, followed by a double-pass attack that fires up “a botnet of hundreds of virtual Chrome workers” from its Google Compute Engine that hit the site. .

“First, the scanner makes a high speed pass, crawling, and parsing the HTML. It then executes a slow and thorough full-page render to find the more complex sections of your site,” said Mann,

“While faster than a real browser crawl, this process is still too slow. So we scale horizontally. Using Google Compute Engine, we dynamically create a botnet of hundreds of virtual Chrome workers to scan your site. Don’t worry, each scan is limited to 20 requests per second or lower.”

“Then we attack your site (again, don’t worry)! When testing for XSS, we use a completely benign payload that relies on Chrome DevTools to execute the debugger. Once the debugger fires, we know we have JavaScript code execution, so false positives are (almost) non-existent.”

The scan however is only meant to complement existing secure design and deployment processes. But it may also make it cheaper for developers when they hire a security pro after a quick clean up.

This article is brought to you by Enex TestLab, content directors for CSO Australia.

Upcoming IT Security Events

March 3rd, March 5th, March 9th 2015

Join CSO for the day@#csoperspectives and hear from @kimzetter @LeviathanSec

3 International Keynote speakers, 36 Key IT Security Industry Speaker, 21 Exhibitors, Security Analysts and many more.. Register today

Dont miss one of the biggest IT Security events in ANZ (registration is free, but seats are limited)

Read more: DDoS top security fear as businesses weigh reputational damage risk

Join the CSO newsletter!

Error: Please check your email address.

Tags cyber attacksweb applicationsOWASP’sattacksblog applicationcloud securityjavascriptcybercrimeurlvulnerability scannerapp engineGoogleapplication vulnerabilitiesGoogle's virtual Chrome

More about CSOEnex TestLabGoogleIT SecurityMann

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Liam Tung

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts