GitLab: [RDoc] XSS in project README files

2017-01-24T07:48:07
ID H1:200693
Type hackerone
Reporter ysx
Modified 2017-02-15T05:28:38

Description

Hi,

While experimenting with parser bypass techniques, I discovered that RDoc markup could be used to inject a stored JavaScript payload into a project README.rdoc file.

Please note that this issue is separate to my earlier report #200565 (XSS with AsciiDoc markup), marked as duplicate.

Steps to Reproduce

  1. Create a new GitLab project
  2. Initialise the project by creating a README file
  3. Set the file title to README.rdoc
  4. Paste the below Payload into the file
  5. Commit the file to the project and click on the "XSS" link

Proof of Concept Payload

XSS[JaVaScriPt:alert(1)] <-- click to test

Thanks!