Security

Airbnb – Chaining Third-Party Open Redirect into Server-Side Request Forgery (SSRF) via LivePerson Chat

bbuerhaus Security , , , , ,
airbnb_horizontal_lockup_print

Update (3/15/2017):

  • LivePerson reached out to me (3/9/17) after this write-up was posted and pushed out changes to patch the open redirect vulnerability. Props to their security team for following up on that!

Ben and I spent more time on Airbnb the past few months and discovered a new endpoint that we had never seen before. After spending a year or so on the program, we were at the point of trying to find a new approach looking for vulnerabilities.

We had the idea of going through all of the js files on Airbnb looking for new endpoints. We were already doing this manually to some degree, but decided to try and automate it. So we built a new tool that grabs js files and looks for relative URLs:

Doing this we quickly found new endpoints that we had missed and found a few new vulnerabilities to report. One of the new endpoints discovered led to finding a Server-Side Request Forgery vulnerability on Airbnb.

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Airbnb – When Bypassing JSON Encoding, XSS Filter, WAF, CSP, and Auditor turns into Eight Vulnerabilities

bbuerhaus Security , , , , , , ,
airbnb_horizontal_lockup_print

We recently started participating in Airbnb's bounty program on HackerOne. We heard a lot about this company in the past but had never used their service before. Overall they have a pretty solid website, but we were still able to discover a handful of issues. There is one vulnerability that we wanted to write about because of the level of protection in front of it. The goal of this write-up is to show others that sometimes it takes a little bit of creativity to discover potential flaws and fully exploit them.

The vulnerability we discovered is a series of Cross-Site Scripting attacks that involved bypassing JSON encoding, an XSS filter, a pretty decent WAF, CSP rules, and eventually getting it to bypass Chrome's XSS auditor.

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DEFCON 24 Badge Challenge Walkthrough

bbuerhaus Puzzle, Security

defcon24

Council of 9 ventured forth to DEFCON 24 to compete in this year’s badge challenge, brought to us each year by 1o57. There was determination among the team to win at DC24 to ensure that last year’s win was not a fluke. After many sleepless nights in Vegas, we emerged victorious for a second year in a row.

Full write-up: https://web.archive.org/web/20160814065806/http://co9.io/post/148716614744/defcon-24-badge-challenge (Archive.org)