Cross-site scripting vulnerability found on www.google.fr

We were able to identify a cross-site scripting (XSS) vulnerability in the main domain of Google: www.google.fr.

Description

Cross-site scripting is a kind of vulnerability that allows an attacker to send malicious code, usually in the form of Javascript, to another user. Exploiting an XSS may lead to private information compromise, cookie theft or even browser take over.

Access Vector: Network

Security Risk: Low

Vulnerability: CWE-931

CVSS Base Score: 3.9

Proof of Concept

Steps to reproduce this XSS issue:

  1. First we need to click the link below using Firefox browser:
https://www.google.fr/#q=Olympiade&mie=oly%2C%5B%22%2Fm%2F03tnk7%22%2C1%2C%22r%22%2C1%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2Cnull%2C0%5D
  1. Then, to insert the following payload in the input field related to search:
<svg onload=alert(document.domain)>

Finally, the alert message box will pop up on the screen.

XSS in Google

Timeline (dd/mm/yyyy)

  • 05/08/2016 : Initial discovery
  • 05/08/2016 : Contact with vendor team
  • 05/08/2016 : Vendor acknowledges with a kind reply: "Nice Catch!" :-)
  • 09/08/2016 : Vulnerability is fixed.

Google Response

Credits