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Re: Universal XSS in all Google Services
From: Nam Nguyen <namn () bluemoon com vn>
Date: Tue, 12 May 2009 17:11:32 +0700

This is much better than its competitor (Yxxxx! Inc).

We reported critical security bug to them twice. All lost to their spam quarantine. When they managed to get back to 
us, and white-listed our addresses, we sent the alert again, and a reminder after. We weren't sure if those two got 
through, but we haven't heard from them either.

Anyway, the bug was resolved (without due credit) in about a month or two.


This serves as a contrast to the prompt response that Google Security Team displayed.


On 9 May 2009 02:03:15 -0000
Inferno () SecureThoughts com wrote:

Universal XSS Vulnerability in all Google Services can compromise your personal information
May 8th, 2009

Vulnerability Reported: 04/18/2009 9.33 pm
Google’s Response: 04/18/2009 10.19 pm (Wow! that was super fast for Saturday :))
Vulnerability Fixed: 05/05/2009 7.05 pm
Change Propogated: 05/07/2009 3.19 pm

I recently reported a cross-scripting flaw to Google, which is now fixed. The vulnerability existed in Google’s 
Support Python Script where a malicious url is not sanitized for XSS character ‘ (single quote) before putting inside 
javascript variable logURL. As a result, it was possible to break the encapsulation of the var declaration and 
execute arbitary javascript commands on the main Google.com domain.

The only limitation was the following characters were either filtered out or url encoded - ” (double quote) < > 
(space) { }. However, this protection could be easily circumvented. I was able to write javascript statements to 
steal the session cookies [since characters such as ' ; . ( ) / = + were still available] and send it to my evil 
website. See the example given below.

Your Google.com domain cookie is the central Single Sign-On cookie to all google services. Once anyone gets it, he or 
she can use it to

1. Steal your emails.
2. Steal your contacts.
3. Steal your documents.
4. Steal your code.
5. Steal your sites.
6. Steal your website analytics.
7. Backdoor your iGoogle Homepage with malicious gadgets.
…. and there should be still some more things remaining that you can play with.

Simple Proof of Concept Code that displays your Google.com cookie in an alert box:-


More real-world example where an attacker will silently transfer your Google.com cookie to his or her evil site:-


I would like thank the Google Security Team for their prompt responses and fixing this serious issue in a timely 
manner. If you think Google took a long time in fixing this vulnerability, think again. This python script is used in 
a lot of places. Try this Google Dork to see the usage of this script in almost all Google Services.

Nam Nguyen
Blue Moon Consulting Co., Ltd

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