Unchecked Buffer in Opera 7.02

["David F.Madrid" <conde0 () telefonica net>]

Tested version : Opera 7.02 Build 2668

Vendor Status : Vendor was contacted on 8-4-2003

Description :

Opera web browser has an unchecked buffer in his code that allow a
malicious website to crash it and in certain circumstances , execute code
with user priviliges .

To reproduce the bug open this link

http://usuarios.lycos.es/idoru/aaAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.zip

Opera crashes with an access violation . Instruction pointer EIP is
overwritten by the file name converted to unicode . That makes only
possible to reference certain addresses in memory to execute . To place
your code to execute in a valid address you have to assign it to an
enviroment variable .That place your code in an address that can be
referenced by EIP ( ~00010040 )



-- 

Regards ,

David F. Madrid
Madrid , Spain