Re: [Full-disclosure] DLL Hijacking vulnerability in Opera

Hello Juha-Matti!

Thanks for mentioning about exploit of Nicolas Krassas for Opera.

I don't read such sites as and, but I read other
sites, such as ( And at his
site (
3APA3A didn't mentioned about such vulnerability in Opera, but mentioned
about many other vulnerabilities, including in such browsers as Firefox,
Maxthon and QtWeb. It looks like he didn't see it (he's checking Bugtraq and
Full-Disclosure) or forgot to mentioned about it (and I waited a lot of
time, after first mentioning about DLL Hijacking, before I conducted my own
research of DLL Hijacking vulnerabilities in different browsers, to gave him
time to publish such exploit if there is such one).

So I was thinking that people forgot to check DLL Hijacking in Opera, so I
reminded about that it was also vulnerable. Besides Opera released update
only at 09.09.2010 (so for long time not showing that they were aware about
it) and they didn't mention in their official advisory about anyone who
informed them about this hole. I.e. they made a look that they found the
hole by themselves.

But there is large difference between my research and Nicolas' research. If
you'll attentively read, you'll find that besides first attack vector,
mentioned in first information about DLL Hijacking (and in many advisories
on this topic which were released later), I wrote about second attack
vector. And also I mentioned about version of Opera where developers
officially fixed the hole and the methods of bypass of this fix.

Best wishes & regards,
Administrator of Websecurity web site

----- Original Message -----
From: "Juha-Matti Laurio" <juha-matti.laurio@xxxxxxxx>
To: "MustLive" <mustlive@xxxxxxxxxxxxxxxxxx>;
Sent: Monday, September 13, 2010 6:43 PM
Subject: Re: [Full-disclosure] DLL Hijacking vulnerability in Opera

It was reported on 24th August already

It takes only a few seconds to check it


MustLive [mustlive@xxxxxxxxxxxxxxxxxx] wrote:
Hello Full-Disclosure!

I want to warn you about DLL Hijacking vulnerability in Opera. As I wrote
Saturday in my post DLL Hijacking in different browsers
(, besides Mozilla Firefox (which was
in version 3.6.9) there is also vulnerable such browser as Opera.

DLL Hijacking vulnerability in Opera allows to execute arbitrary code via
library dwmapi.dll. Attack will work in Opera on OS Windows. For attack
there can be used the same dwmapi.dll, as for Firefox (based on the
of Glafkos Charalambous).

When I informed Opera, I draw their attention as to the hole itself, as
possibility to attack version Opera 10.62 (which released recently),
this hole was fixed by developers.

There are possible two variants of attack:

1. Attack will work at opening in browser the file of web page (htm,
mht, mhtml) or other file, alongside with which there is file dwmapi.dll.

2. If file dwmapi.dll is placed at desktop or in any folder which is in
PATH, then code will work at every starting of the browser.

From second variant of attack it's clear, that in some applications
(such as
Opera) it's possible to conduct DLL Hijacking attacks with other method,
then one which was mentioned in August. I.e. code will execute not only
placing of dll-file alongside with file designed for opening in
but also if dll-file is placed at desktop or in any folder which is in
And code can be executed even at starting of application (as in Opera),
without opening of any files.

Vulnerable are Opera 10.61 and previous versions.

As I checked in Opera 10.62, which released at 09.09.2010, this version
not vulnerable (to both variants of attack). Only if to place dll-file in
folder Opera or in System32, only then the code will work (so the attack
take place on systems with FAT32 or when attacker will be having
rights on systems with NTFS).

Best wishes & regards,
Administrator of Websecurity web site

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