Title: YaBB Flash File Script Injection Vulnerability
Severity: HIGH
Description:
YaBB (Yet Another Bulletin Board) is freely available web forum software that is written in Perl. YaBB will run on most Unix/Linux variants, MacOS, and Microsoft Windows 9x/ME/NT/2000/XP platforms. Versions of YaBB are subject to a script injection issue via Flash files.
Macromedia Flash uses a built in scripting language called ActionScript. ActionScript contains numerous functions which enable developers to create complicated animations, simulations, games etc., one of which is getURL(). The getURL action accepts a target URL as a parameter, and the user's Flash player is redirected to the target source in order to display the file appropriately.
It is possible to specify javascript:// URLs as the parameter to this function. When the function executes, the browser is redirected to the URL, and the specified code will execute. This will generally be within the context of the site hosting the Flash file.
YaBB permits users to upload Flash content, however, it is possible to craft a Flash file in such a way that malicious JavaScript, included in the getURL action, will execute in the browser of the user viewing the message.
This is accomplished by posting a message to YaBB containing a maliciously crafted Flash file. Upon a user viewing the post, the JavaScript included in the Flash file will execute within the context of the site running YaBB.
This issue may be exploited to steal cookie-based authentication credentials from legitimate users of YaBB.
Affected Products:
- YaBB YaBB 0.0.01 Gold Release
References:
- Obscure: Bypassing JavaScript Filters ? the Flash! Attack
- YaBB: YaBB Homepage
Juniper Networks provides this content via a wide variety of sources and production methods. If notified of errors or omissions in the content of this page, Juniper Networks, at its discretion, will modify or remove the page or leave the content as is, depending on various factors including but not limited to the reputation and authority of the party providing the notification. Please use the contact information displayed elsewhere on this page to report any errors or omissions regarding the content on this page.
