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anthony
Moderator
USA
1808 Posts
Status: offline |
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joe_elway
Honorable But Hopeless Addict
Ireland
6369 Posts
Status: offline |
 Posted - 02/22/2008 : 04:45:28 AM
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That is pretty amazing! So mugging an executive while he uses wifi in Starbucks and quickly attacking the laptop leaves it vulnerable, no matter if you've used disk encryption or not ... including opensource, MAC and BitLocker.
The same goes for a server in a branch office with no physical security to speak of. You've used a W2008 RODC with BitLocker and it get's attacked at the weekend. The "vulnerability" leaves it open to almost instantaneous attack. Odd's are it gets attacked at a weekend with this method allowing the attackers to hit the rest of the network before admins know of a theft and can kick in the recovery steps to isolate security principles cached on the RODC.
Ouch. Physiscal security remains the key to your defence. |
Aidan Finn
MCSE, MVP (Virtual Machine: Systems Administration)
IT Blog: http://www.aidanfinn.com
My Photography: http://www.aidanfinnphoto.com/
Windows User Group - Ireland: http://ws-ugi.spaces.live.com
Twitter: http://twitter.com/joe_elway |
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wkasdo
Moderator
Netherlands
5720 Posts
Status: offline |
Posted - 02/22/2008 : 05:48:14 AM
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True, but not really new. Theoretically, to be sure bitlocker protects your machine, it needs to be turned off. Not hibernated or standby, OFF. This goes for any other HD protection scheme. The new thing here is that somebody outside the CIA actually managed to pull off a hack!
Re RODC: it's not that bad. IF the thief can hack the machine, IF he bypasses bitlocker, and IF it has cached passwords of local people, and IF the thief manages to reset those, the worst he can do is to act as a local user. The thief cannot use attacks that will work an full DC (sidhistory injection) because any change you make on the RODC will not replicate.
> Physiscal security remains the key to your defence.
Amen.
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Xenophane
Honorable But Hopeless Addict
Denmark
2661 Posts
Status: offline |
Posted - 02/22/2008 : 06:06:34 AM
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| What I would'nt give to be a fly on the wall when people figure out such things... |
SIG> George Bernard Shaw : The power of accurate observation is commonly called cynicism by those who have not got it. </SIG>
You can read my blog at www.xipher.dk |
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wkasdo
Moderator
Netherlands
5720 Posts
Status: offline |
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Mark Minasi
Chief cook and bottle washer
USA
9257 Posts
Status: offline |
Posted - 02/22/2008 : 4:59:57 PM
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Good heavens. Y'know, there are days that I'm embarrassed to be "a security person."
Wouldn't it be easier to just clip electrodes to the user's genitals, hold 'em down and turn the rheostat up?<g> |
Mark
tweetin' at mminasi |
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wkasdo
Moderator
Netherlands
5720 Posts
Status: offline |
Posted - 02/22/2008 : 5:39:01 PM
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| Easier, but not as much fun ;-) |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/22/2008 : 5:43:08 PM
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| Depends on the type of person you are? A rheostat turner? Or one who likes electrode clipped to genitals? |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/23/2008 : 12:02:35 AM
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I've been giving this a lot of thought and am thinking this may not be as easy on Vista as they make it appear but only if you have a TPM chip. As I understand BitLocker the TPM chip stores the key so (I'm thinking) the key is never in memory and there is no known way to access the registers in the TPM chip to get the key. Can anyone assist in my reasoning?
Dougggg |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/23/2008 : 01:51:19 AM
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| After researching this a more I found BitLocker is NOT vulnerable if the machine goes through a complete boot process. Meaning it's not hibernated, in sleep mode or in quick boot mode. It you think about it, it makes sense. If the machine has to go through a complete boot process it has to Bitlocker unlock the drive. In sleep, hibernate or quick boot the drive is already unlocked. Unfortunately users will not understand the difference. A GPO would fix that. Remove all options except shutdown and power off when lid is closed. Watching the video again listen at 4:33 and she says Vista is may not be vulnerable. |
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JamesNT
Moderator
USA
2326 Posts
Status: offline |
Posted - 02/23/2008 : 12:15:01 PM
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I hope Vista is not vulnerable to this attack. I don't really care for sleep mode but I love hibernate. It would be a shame to lose such a useful feature.
JamesNT |
"People demand freedom of speech to make up for the freedom of thought which they avoid."
- Soren Aabye Kierkegaard (1813-1855)
New blog at http://jamesnt.wordpress.com |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/23/2008 : 12:29:07 PM
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JamesNT
Hibernate doesn't offer any protection. The drive is already unlocked. BitLocker can protect the drive only if the machine was is was completely "shutdown" and "powered off". If the drive is in hibernate, sleep mode or quick/fast boot the drive is already unlocked. Listen in the video around 4:33, they discuss it.
What they don't discuss is the TPM chip. I'm thinking your machine has a TPM 1.2 chip. I'm not sure, but I don't think the key is copied from the TPM chip to memory, I think it stays in the TPM chip. When you pull the ram you don't get the key. Maybe Mark knows the answer, I'm only speculating.
Douggg |
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wkasdo
Moderator
Netherlands
5720 Posts
Status: offline |
Posted - 02/23/2008 : 1:46:48 PM
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>Hibernate doesn't offer any protection. The drive is already unlocked. BitLocker can protect the drive only if the machine was is was completely "shutdown" and "powered off".
Not quite. If it is configured such that you have to enter the PIN on resume from hibernate, you are safe. |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/23/2008 : 1:56:07 PM
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wkasdo,
Does the TPM chip make a difference?
Doug
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wkasdo
Moderator
Netherlands
5720 Posts
Status: offline |
Posted - 02/23/2008 : 2:45:39 PM
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| Yes. Without TPM you need an external USB device to hold the key. |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/23/2008 : 3:31:32 PM
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Please correct me if I am wrong on this but with the key on a USB stick the key is copied into memory and the key could be found with their software. Using the TPM chip, the key is in the TPM chip and never transfered to RAM so this attack will not work.
Douggg |
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Xenophane
Honorable But Hopeless Addict
Denmark
2661 Posts
Status: offline |
Posted - 02/23/2008 : 3:41:00 PM
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According to the article, if you use Bit Locker in Basic mode, the keys are stored on the TPM. The keys are then loaded into memory during the windows boot, meaning that the keys are located in memory when you get to the login screen. This actually means that if you use basic mode, you are more susceptible to the attack since the keys are stored on the TPM just waiting for someone to boot the machine.
So the attack vector is, boot the machine... wait for windows to load (Keys are transferred from TPM to memory) pull the power... The keys reside in RAM, boot from an external device with their memory/key extraction tools. Extract the keys... Mount the volume with the correct key. |
SIG> George Bernard Shaw : The power of accurate observation is commonly called cynicism by those who have not got it. </SIG>
You can read my blog at www.xipher.dk |
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Xenophane
Honorable But Hopeless Addict
Denmark
2661 Posts
Status: offline |
Posted - 02/23/2008 : 3:48:30 PM
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The article then goes on to say that Microsoft is aware of this, and they recommend using BitLocker in advanced mode where you have to type in a PIN at boot (I guess this a security measure to make sure that the TPM does not "hand-out" the key to memory before it is sure you know the PIN).
If you want to read more about it, you can look here at Douglas MacIvers original paper on attacking BitLocker from 2006
EDIT
According to the article hibernation should be safe as well.. |
SIG> George Bernard Shaw : The power of accurate observation is commonly called cynicism by those who have not got it. </SIG>
You can read my blog at www.xipher.dk |
Edited by - Xenophane on 02/23/2008 3:55:35 PM |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/24/2008 : 10:43:38 AM
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I was talking to a fried of mine and he seemed to think there was a way to "lock" a hard drive. Looking into this I found hard drive locking has been built into the ATA spec for the past 10 years or so. (ATA-Packet Interface ATA-PI) This locks the drive (to prevent access) not encryption. From what I read so far it is very good protection.
The machines BIOS has to support it. Many laptops have had support for this for many years, and desktops began supporting this just recently.
There’s a new ATA spec for hard drive encryption, check your machines BIOS to see if it supports it.
Douggg |
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Xenophane
Honorable But Hopeless Addict
Denmark
2661 Posts
Status: offline |
Posted - 02/24/2008 : 4:57:44 PM
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Douggg just spend a couple of hours reading about ATA "Security Mode feature set". Hope it is OK if I elaborate on some a few things.
The Security Mode feature set was initially created for 2½" disks (laptop disks) in about 1996.
quote:
The optional Security Mode feature set is a password system that restricts access to user data stored on a
device. The system has two passwords, User and Master and two security levels, High and Maximum. The
security system is enabled by sending a user password to the device with the SECURITY SET PASSWORD
command. When the security system is enabled, access to user data on the device is denied after a power
cycle until the User password is sent to the device with the SECURITY UNLOCK command.
A Master password may be set in a addition to the User password. The purpose of the Master password is to
allow an administrator to establish a password that is kept secret from the user, and which may be used to
unlock the device if the User password is lost. Setting the Master password does not enable the password
system.
The security level is set to High or Maximum with the SECURITY SET PASSWORD command. The security
level determines device behavior when the Master password is used to unlock the device. When the security
level is set to High the device requires the SECURITY UNLOCK command and the Master password to
unlock. When the security level is set to Maximum the device requires a SECURITY ERASE PREPARE
command and a SECURITY ERASE UNIT command with the master password to unlock. Execution of the
SECURITY ERASE UNIT command erases all user data on the device.
The SECURITY FREEZE LOCK command prevents changes to passwords until a following power cycle. The
purpose of the SECURITY FREEZE LOCK command is to prevent password setting attacks on the security
system.
What this seems mean is that you can set two security modes on the drives High & Maximum
In High security mode both the "user" and the "master" password is able to unlock the drive.
In Maximum only the "user" password will unlock the drive, the "master" password needs to be sent with a delete all command, that overwrites the entire disk with 0's and then allows access to the disk.
IBM started making this widely available in their 3½" disks in 1998 as well, Microsoft later asked Seagate to build the security into their 3½ drives for the Xbox to protect them, later WD followed suit.
This means that practically all disks today have the "security features" available.
As a security precaution the devices have a function called "SECURITY FREEZE LOCK", when this command is sent to the device it will not accept any changes to the password until next boot. The problem is that most PC manufacturers have not added this feature to the BIOS of PC's meaning that it is theoretically possible to set the password when the PC is running, rendering the disk unreadable at next boot.
Luckily for us the windows API that sends "ATA" commands does not support the commands:
quote:
SECURITY SET PASSWORD
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SECURITY UNLOCK
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SECURITY ERASE PREPARE
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SECURITY ERASE UNIT
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SECURITY FREEZE LOCK
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SECURITY DISABLE PASSWORD
So in order for someone to abuse it, that person would have to gain admin access to the PC, install a kernel mode driver that can communicate directly with the disk, and the BIOS should not have sent the "SECURITY FREEZE LOCK" command.
On the security topic Heise.de tested it, and found that it was not enough to remove the circuit board and replace it with a board from an unlocked drive. So password data is stored on the drive platters as well.
They sent the drive to IBAS (Norwegian data recovery company) who were able to recover the key.. (They call it a trade secret)
As with most closed systems it is not known is there is a master master password, though vendors claim there isn't.
So if you want to add another security hurdle besides encryption, you find a PC with a BIOS that supports the security features, set security the maximum, encrypt the disk with your favorite encryption software. This should scare off most except the mosts adamant hackers or big brother.
There is a tool called WinAAM (German) which is used to manipulate drives acoustics, it will also tell you the current security setting of the drive (You can use it to see if your BIOS sets the SECURITY FREEZE LOCK on the drive) If it doesn't you might consider to check for a BIOS update, and you might be lucky that the new BIOS sets it.
From what I have read I am convinced that the ATA security standard is not unbreakable, with the right experience/equipment it is still possible to bypass the ATA password, and it does not mitigate the initial problem of the possibility to extract encryption keys from RAM. But it is definitely an extra layer of security. |
SIG> George Bernard Shaw : The power of accurate observation is commonly called cynicism by those who have not got it. </SIG>
You can read my blog at www.xipher.dk |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 02/24/2008 : 5:24:22 PM
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Xenophane
Thank you. This was excellent.
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JamesNT
Moderator
USA
2326 Posts
Status: offline |
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RTHJr
Here To Stay
USA
165 Posts
Status: offline |
Posted - 03/10/2008 : 10:01:58 AM
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If the ATA Security Mode that is BIOS supported relies upon settings that are actually stored on the disk, then an old technique of unlocking password protections managed in the BIOS might will be blocked with this technology, if I understand it correctly. In the past, whenever I inherited a computer where the system BIOS was locked by a password, all I had to do was download the latest BIOS and flash the BIOS and BAM!, the BIOS is set to defaults. So I [had] wonder[ed] if the ATA Security Mode is impervious to such a technique.
Edited for Douggg's response below. Thanks Douggg! That confirms what I was getting. |
Ralph T. Howarth, Jr.
www.cfcmi.org |
Edited by - RTHJr on 03/10/2008 11:48:21 AM |
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Douggg
Major Contributor
779 Posts
Status: offline |
Posted - 03/10/2008 : 11:07:21 AM
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If a drive is locked with the ATA lock command "lock" is in the drive not the machine's BIOS. (Same applies to the ATA encryption command.) If you upgrade the BIOS of move the drive the drive is still locked or encrypted.
There are two other way one could defeat the drive lock....
+ Can the drive be unlocked by upgrading the drive's BIOS? No, the drive would need to unlock the drive to upgrade the BIOS.
+ What about swapping the circuit board on the drive with one that is unlocked? Don't work either, the unlock key (or if encrypted, the encryption key) is stored on the drive platter.
Crypto people have told me the only way to get the key is a brute force attack or take the drive to a clean room and read the bits off the drive. But if you go to that measure you have the entire hard drive.
ATA drive lock command and ATA drive encrypt commands are secure and can not easily be defeated.
Douggg
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Bitlocker & other disk encryption cracked?
