PHPBB2 - Image Tag HTML Injection

source: https://www.securityfocus.com/bid/4858/info


It is possible to inject arbitrary HTML into phpBB2 forum messages via the use of BBCode image tags. A similar issue is described in Bugtraq ID 4379 "PHPBB Image Tag User-Embedded Scripting Vulnerability". However, phpBB2 was found to not be vulnerable to this previous issue.

A double-quotation (") character may be used to close the HTML statement that is created when the BBCode is translated. The attacker may then include arbitrary HTML after the double-quotation.

The attacker may exploit this issue to inject script code into forum messages. When such messages are displayed by a web user, the attacker's script code will execute in their browser in the context of the website.

phpBB versions prior to the phpBB2 series may also be affected by this vulnerability. 

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