Security researcher says Microsoft built a Bitlocker backdoor, releases exploit

https://www.techspot.com/news/112410-security-researcher-microsoft-secretly-built-backdoor-bitlocker-releases.html

by nolok • 2 months ago

594 244 2 months ago

superkuh3• 2 months ago

As long as Microsoft will continue to use dark patterns to convert local accounts to online accounts and automatically, without user consent, encrypt the storage drives preventing any computer use until the user goes to aka.ms and through the hoops, this is a good thing.

No one should have their data encrypted and kept from them without consent unless they do something. Microsoft does that now. They may not be requring a monetary ransom like others, but it is a ransom nevertheless.

I know this is controversial. Bitlocker helps protect one's property and information when used intentionally. And that being impacted is a shame.

mynameisvlad3• 2 months ago

You only need to use the aka.ms link if you lost your recovery key. That feature also can be disabled without disabling Bitlocker as a whole.

superkuh3• 2 months ago

How would a user that never set it up in the first place have a recovery key? I honestly am asking and don't know.

I recently (last week) had to drive over to a parent's house and "fix" their (pre-online accounts) win 11 computer used for sewing because it had become a blue screen saying aka.ms was required. They did not know how it happened and are not very technical users so I imagine they were tricked by some click-through dialog. It is not something they would ever do intentionally. All that computer ever does is run sewing pattern/control software.

whycome• 2 months ago

The nagging to upgrade is insane. Even the 'dismissal' option is a dark pattern still designed to make you click the wrong thing

archerx4• 2 months ago

Maybe I’m an outlier but I don’t want my drives encrypted at all. I rather have all my data be accessible if things go catastrophic, I.E. having to pull the drive out of a broken computer and put it in another computer to access the files. I just want it to be plug and play.

lstodd• 2 months ago

What's not plug and play if using some sensible fde like idk, dm-crypt? You are only a passphrase away from mounting that drive in any other system you plug it into.

pessimizer2• 2 months ago

That's my question, because my root is encrypted, I move encrypted disks all the time, and have a couple of encrypted external drives. It's trivial.

But I'm sure that some of the millions of things that I've missed as windows has become what it has become makes this simplicity seem like a scifi absurdity. I don't think that they can even log into their own computers without asking Microsoft for permission over the network. I'm sure the idea of encryption must have been overcomplicated to the point of absurdity in order to trap customers too, I just don't know about it.

I suppose you should just count your blessings (of ignorance) and be available to help your friends with cryptsetup if they decide to flee windows.

Glohrischi4• 2 months ago

My harddrives (laptop, work laptop, desktop, server) contain emails, browser sessions, saved passwords, personal data from family and friends.

I do not want someone stealing my laptop on a train ride potentially being able to have all of that data.

With a proper real backup strategy, i have everything save. I do not need easy access to a hard drive from a broken computer.

But hey you do you :)

xingped• 2 months ago

Cool. Everyone's threat model is different. As long as we're not writing passwords on sticky notes attached to the monitor, I don't think there's any need to be throwing stones.

NBJack• 2 months ago

Are you saying you bring your desktop on a train ride as well? Laptops with encryption make sense; if you need to encrypt your desktop, I have questions.

archerx4• 2 months ago

My data is mundane and mostly my art projects and photography. I don’t believe I am important or interesting enough for someone to do anything with my data if they somehow managed to get it also I don’t have emails, saved passwords, banking info or that kind of sensitive info on my computers so meh I guess.

aniceperson• 2 months ago

the point is having a choice and the choice actually doing what it claimed.

skeledrew• 2 months ago

Same here. If anything happens I want a decent chance to be able to recover my data. The most I may do is create encrypted files, and some of them I've forgotten the passwords for, which makes me even more wary.

tekne• 2 months ago

I mean... you can use an encryption scheme compatible with this (if you know the password).

I suppose this makes some sense for home computers (burglars and police raids are rare) but for a laptop, you really don't want thieves getting all your details.

Ironically -- this probably was paranoid a few years ago, but now -- "ChatGPT, use this prepared prompt to extract all useful info from this hard drive"

The_President2• 2 months ago

Additional problem is if physical access is obtained, illegal material could be covertly added to the drive then picked up by the built in scanners in your OS. Depends on how important you are.

hiq2• 2 months ago

If "things go catastrophic" your hard drive is not usable at all anymore. At the very least some files can't be recovered at all. So you need backups in any case. Once you have backups, you might as well encrypt your hard drives, especially if you store these in different locations (which you should).

An advantage of encryption is that it makes it easier to give away or resell devices. With recent encryption schemes (well the ones on Linux, given this article), I feel confident that overwriting the encryption keys gets me close enough to not leaking my data once I get rid of an old hard drive.

archerx4• 2 months ago

That’s not true. I’ve had many computers that refuse to turn on and I was able to recover the files by removing the drive and loading it into a USB hard drive reader and recover the files.

deng• 2 months ago

But it's also plug&play for anyone stealing your laptop, see for instance

https://news.ycombinator.com/item?id=39941021

jsmith992• 2 months ago

So long as you've backed up the key you can fairly easily decrypt on any machine.

rpdillon3• 2 months ago

I was happy to give up my side-hobby of drilling drives after FDE became standard everywhere. Plug and play is great, but you don't want it to be plug and play for whoever pulls your drive out of the trash.

mordae• 2 months ago

That's called LUKS2 and it's the default on Linux. You just type passphrase on boot. It's not tied to the motherboard.

archerx4• 2 months ago

What if you forget the passphrase after not using it for many years and you suddenly need a file on the drive?

seanieb2• 2 months ago

At what point will Security professionals start turning down roles that involve “securing” MS Products? I’m already at this point.

Securing Microsoft products is busy work while waiting to have it undercut by the next wave of MS’s insane tech debt and greed. And now backdoors!

microtonal3• 2 months ago

As opposed to iOS, which does iCloud backups that are not E2E encrypted by default, so that law enforcement can request your chats (except Signal because they opt out), browser history, etc.?

You can enable ADP for E2E encrypted backups, but it's probable not going to help you much, because the people you are communicating with likely didn't.

This is not to defend Microsoft, more to say that all these companies were part of PRISM.

seanieb2• 2 months ago

This is not to defend Microsoft

But you are defending MS, conflating a bunch of things, mainly full disk encryption and cloud backups.

There's a big difference between Apples cloud backup which has documented behavior and a backdoor. I'm also fairly confidant in Apple's full disk encryption, they've gone to court to defend it. There also a lot more data points we can use to judge Apple vs Microsoft on privacy and security, and MS comes out looking bad.

gruez5• 2 months ago

You can enable ADP for E2E encrypted backups, but it's probable not going to help you much, because the people you are communicating with likely didn't.

That just sounds like a fundamental issue with security in general, not specific to Apple/Microsoft.

vorticalbox• 2 months ago

Not in the UK sadly, ADP is disabled.

lokar• 2 months ago

You are confused. They are not "security" roles, they are compliance roles. That's all most enterprise customers really care about. They satisfied all of the compliance rules, and are following "best practices" (influenced by MS), anything that happens is not their fault.

wongarsu• 2 months ago

And having more busywork to do is actually a good thing. Having people employed to do said busywork shows how serious they are about "security", without requiring any skills that are difficult to hire

yellow_lead• 2 months ago

For enterprise, there seems to be so much money in doing it, that I don't think people are going to start turning it down just because it's troublesome.

TacticalCoder• 2 months ago

And now backdoors!

"now"?

Shall we have a discussion about the excuse Microsoft gave as to why keys they claimed, back then, were "secondary keys" belonging to Microsoft, were called ..._NSAKEY when a version of Windows NT shipped, by mistake, with debug symbols on?

One time, just freaking one time, a version of Windows shipped with debug symbols on and, by chance, there had to be cryptographic keys named "NSAKEY" in there.

Yeah.

Now that people constantly turning a blind eye on the wrongdoings of the state are of course going to say that it's totally normal and just repeat the, carefully crafted, excuses from Microsoft from back, that it was totally not a backdoor etc.

masfuerte• 2 months ago

The bit I never understood in this story is the accidental leak of the debug symbols. Microsoft publishes them anyway. They are not a secret. Back in the day, the symbols shipped on the CD, and they published updated symbol packages for service packs. Nowadays they are published on the web and their debuggers download the symbols automatically.

StayTrue• 2 months ago

Had to look this up myself.

https://en.wikipedia.org/wiki/NSAKEY

TiredOfLife• 2 months ago

Microsoft has shipped debug symbols plenty of times.

embedding-shape• 2 months ago

Seems this traces back almost a week, from Nightmare-Eclipse who is the researcher who found this:

Tuesday, 12 May 2026 - "Here are the links, yes, two vulnerabilities this time [YellowKey] [GreenPlasma] [...] Next patch tuesday will have a big surprise for you Microsoft"

Wednesday, 13 May 2026 - "I can't wait when I will be allowed to disclose the full story, I think people will find my crashout very reasonable and it definitely won't be a good look for Microsoft."

Author's blog: https://deadeclipse666.blogspot.com/

First post in March 2026 is "[...] someone violated our agreement and left me homeless with nothing. They knew this will happen and they still stabbed me in the back anyways, this is their decision not mine."

I'm not sure what to make of it, is this someone essentially "leaking" things from the inside? Sure sounds like it, and others are able to reproduce the results.

krisbolton• 2 months ago

I read it as the author is / was going through the vulnerability disclosure process with Microsoft and they're annoyed for unclear reasons and decided to publicly disclose, rather than being an insider.

mr_mitm2• 2 months ago

How would that leave them homeless?

Alifatisk• 2 months ago

Can’t wait to read the blogpost of what have truly happened and motivated this person to expose M$ like this

bri3d4• 2 months ago

Previously discussed numerous times on HN, like: https://news.ycombinator.com/item?id=48130519

Whether this is a backdoor or not boils down to whatever your usual proclivities about "bug or backdoor" are; it's not like "if microsoft = 1 hack bitlocker" like the tech press seem to love to report.

This is a bug in the NTFS transaction log replay functionality in the Windows Recovery Environment WinRE, where it will read NTFS transaction logs from an external volume and apply them to the mounted filesystem. This allows the attacker to perform an authentication bypass against WinRE. With BitLocker without PIN or Password, _any_ authentication bypass becomes a disk encryption bypass, since the disk is unsealed by the bootloader (this architectural "flaw" is true for Linux with the same configuration, as well, like Ubuntu installed with their newish Hardware Disk Encryption checkbox in the installer).

In lieu of additional evidence, whether you think the NTFS transaction log issue is a planted backdoor or a simple enumeration bug depends on your conspiracy theory level, like most things in exploit development. To me, it seems like a plausible bug. The weaknesses in boot-time unseal are well known and obvious and this is just one of many, so I don't see it as an earth-shattering revelation, although it is a fun bug.

bastawhiz2• 2 months ago

It's very strange that the same component exists in Windows without the issue, though. Like the author, I'm finding it difficult to come up with reasons why they'd be different.

solenoid0937• 2 months ago

The author says he is able to use a similar vuln to bypass the PIN requirement. Most certainly a backdoor if true.

866-RON-0-FEZ6• 2 months ago

This is the most succinct, plain-English explanation I've seen to date. Thank you for posting this.

BLKNSLVR• 2 months ago

Title sounds conspiratorial, but it lines up well with the controversy around TrueCrypt's discontinuation which, I believe, specifically called out BitLocker as an alternative to use in future.

otakucode• 2 months ago

That was my immediate first thought. "Oh, is Bitlocker Not Safe Anymore?"

ekjhgkejhgk• 2 months ago

I'm not aware of the connection between truecrypt and bitlocker, want to enlighten us?

akersten• 2 months ago

Long time ago TrueCrypt suddenly and abruptly shut down with a vague goodbye message saying "everyone please move on and use bitlocker instead"

Prevailing theory is they were pressured to put in a backdoor and couldn't disclose it, so they had to make a seemingly ridiculous statement (because who in their right mind would trust bitlocker) to call attention that "something is very wrong"

alamortsubite• 2 months ago

You're probably thinking of VeraCrypt, which is a fork of TrueCrypt. I don't think BitLocker is related.

rzzzt• 2 months ago

https://en.wikipedia.org/wiki/TrueCrypt#End_of_life_announce... - they are referring to this event, and the SourceForge page is still displaying the message along with a guide on how to enable BitLocker.

ricksunny• 2 months ago

Why is 'conspiratorial' posed as a prime facie _bad thing_ to posit?

pocksuppet2• 2 months ago

Mental inertia. It used to be a bad thing to theorize conspiracies without evidence, but now we actually have evidence of so many conspiracies similar to this that it's probable there are lots more.

markant• 2 months ago

"Security professionals generally recommend avoiding reliance on any single encryption system and instead evaluating well-reviewed full-disk encryption alternatives such as VeraCrypt".

If they put a backdoor into FDE it would make more sense to advise people to stop using windows at all and using Linux instead. If they put a backdoor in FDE you can be sure there is not just one backdoor in the operating system itself. You shouldn't trust proprietary software at all. You shouldn't even trust open source if it isn't properly audited.

tptacek2• 2 months ago

I don't use Microsoft products generally but not with even with your computer would I run VeraCrypt.

MrZander• 2 months ago

What? Why?

recursivegirth2• 2 months ago

Ever since the TrueCrypt fiasco years ago, I have no trust in that brand.

rpdillon3• 2 months ago

Curious to see this take from you! I followed TrueCrypt for years, but always thought it was very strange that they were anonymous, and then the mysterious shutdown happened, and I have no idea what to make of VeraCrypt. It's been in my "possibly good, but too many weird flags around the whole project" bucket.

Anything in particular that makes you wary? I'm aware of the 2016 and 2020 audits (https://ostif.org/the-veracrypt-audit-results/ is the 2016 one, I believe), but those seemed to suggest things were getting better over time. Curious what other signals to look for.

cantrevealname• 2 months ago

not with even with your computer would I run VeraCrypt

This has got to be the most surprising encryption-related comment I've ever read from you. Please tell us what you're thinking about VeraCrypt. What would you say about TrueCrypt v7.1a, the last known good release?

Hypomixolydian4• 2 months ago

[citation needed]

paulpauper• 2 months ago

Or use something like veracrypt which is opensource

sigmoid102• 2 months ago

Don't be so sure. Veracrypt is a fork of Truecrypt, which was famously shuttered after security rumours started spreading - all the way to NSA interventions aimed at the developers. One rumour even said they intentionally shut it down to prevent a possible backdoor compromise. Popular encryption tools for public use will always be priority targets for three letter agencies. And there's more than enough legal leeway here to compromise anyone and anything. If it is popular enough for you to see it mentioned outside of dedicated nerd forums, you can bet these agencies already target it.

kmoser• 2 months ago

Nothing against VeraCrypt, but isn't it also a single encryption system?

zb3• 2 months ago

This doesn't surprise me at all. Microsoft is a Chinese company and Chinese companies have to work with the government on such matters. Oh sorry, I meant an US company, whatever..

dboreham2• 2 months ago

Another way to look at this is that Microsoft, Google, Apple, et al are in the business of providing products and services to regular people, for a low cost. This means they end up providing ways to escrow keys, recover locked accounts and so on that are weak. Not because they want to provide back doors for TLAs but because to provide strong security would be so expensive they couldn't meet the price point for regular customers. If, for example, MS only provided disk encryption that relied on a smart card or a memorized strong passphrase at boot/wake, they'd go out of business providing support to people who forgot their passphrase and being sued by people who lost their data.

jsmith992• 2 months ago

This doesn't sound bitlocker specific, sounds more like a login bypass. If you rely on TPM without PIN then it gets decrypted automatically. This should be fine normally as attackers shouldn't be able to get past login screen. But this exploit shows a way allegedly to get a unrestricted shell in the recovery environment.

The researcher claims a way to bypass PIN too but hasn't revealed it.

14• 2 months ago

Probably since disclosure didn't result in a bounty may as well sell it to someone who would pay.

pixel_popping• 2 months ago

Well I doubt anyone would be surprised with a backdoor in MS product, there have been many of them already, I frankly doubt anyone with "disk encryption" on Windows would think that it's NSA-proof (or script-kiddy clever, as shown in this article :))

majorchord5• 2 months ago

there have been many of them already

source: trust me bro

mschuster91• 2 months ago

The vulnerability may also work without a USB drive if the FsTx files are copied to the Windows EFI partition and the encrypted disk is temporarily disconnected from the system. After placing the FsTx folder, an attacker would need to reboot a BitLocker-protected machine, enter the Windows Recovery Environment, and follow a specific sequence of inputs.

At the point where you're able to mount the EFI partition and effectively modifying the bootloader, it's game over anyway - just run `manage-bde -unlock`, you already have to be root to mount the EFI partition.

m3kw9• 2 months ago

That should be the fastest way to make them patch it.

patzentango2• 2 months ago

I just digged into the exploit a little bit more and what it does it targets BitLocker in TPM only mode. That means that there is no preboot authentication or anything. What happens is secure boot validates the boot chain and the TPM gives out the encryption keys by itself. When you have physical access, it doesn't really make a difference. If there is a stick you can boot from and drop into an emergency shell or if you have to buy a $5 microcontroller and solder it to certain pins on the main board to sniff the TPM keys. What Microsoft is doing here in general they are selling something that is not secure. They are selling it as as full disk encryption but it's not. Someone who can flash a flash drive with an exploit and drop to a shell and use it to browse and copy files. Can also just buy that microcontroller and watch your YouTube with you How to solder. So the "exploit" isn't The problem here the problem is the false sense of security that Microsoft is selling.

kro2• 2 months ago

Ubuntu also released TPM based FDE a few versions ago. I had these thoughts then and decided against using it. Typing my passphrase on boot is muscle memory and gives me simple security I can trust.

Also can recover data without my mainboard.

Maybe a hybrid (secureboot-TPM+phrase) slot for day to day to also prevent against evil maid attacks, and another slot with a backup passphrase would be acceptable.

gruez5• 2 months ago

Typing my passphrase on boot is muscle memory and gives me simple security I can trust.

It's not an either-or. You can combine TPM with passwords which makes it far more secure than password alone. A TPM can enforce password guessing limits, otherwise a password needs to be absurdly long to be secure against GPU bruteforcing attacks. It also prevents someone from swapping out the bootloader with a backdoored version that steals your passwords.

Also can recover data without my mainboard.

You're supposed to keep a backup of the encryption key when using TPM, in case it fails.

gruez5• 2 months ago

If there is a stick you can boot from and drop into an emergency shell

This won't work because the TPM will only give you the keys if you're booting an "approved" OS, specifically the PCR states that the encryption keys are bound to.

or if you have to buy a $5 microcontroller and solder it to certain pins on the main board to sniff the TPM keys.

That only works with dTPMs. fTPMs aren't vulnerable to this, and are far more popular than dTPMs.

patzentango2• 2 months ago

I was talking about the signed recovery shell the article is talking about. Sadly most business laptops still use dtpms. Also if they use ftpms you can simply use a ram scraper. The attack surface is huge either way.

bootsmann2• 2 months ago

fTPMs also have similar issues. The real takeaway is that if your threat model includes actors capable of executing attacks against BitLocker you need to put a password/pin on it in addition to the TPM.

https://arxiv.org/pdf/2304.14717

dataflow• 2 months ago

They claim they have TPM + PIN exploit too, though how credible it is remains to be seen.

https://deadeclipse666.blogspot.com/2026/05/were-doing-silen...

866-RON-0-FEZ6• 2 months ago

What Microsoft is doing here in general they are selling something that is not secure. They are selling it as as full disk encryption but it's not.

But you can configure Linux LUKS in the exact same way.

This doesn't seem an attack on BitLocker so much as it is an attack on the secure boot chain.

The value of PIN-less unlock is if your threat model is limited to the disk being disposed of or removed from the machine or otherwise separated from the TPM.

Entering a PIN is inconvenient or impossible if more than one user regularly uses the device. Hence, control to validate access is transferred to a trusted OS component.

fortran773• 2 months ago

It's a very serious bug, but Bitlocker is full-disk-encryption. It's just possible to bypass the authentication.

pessimizer2• 2 months ago

Security professionals generally recommend avoiding reliance on any single encryption system and instead evaluating well-reviewed full-disk encryption alternatives such as VeraCrypt.

What does this even mean? Nobody is using multiple encryption schemes on top of each other, are they?

dboreham2• 2 months ago

I've heard this before, so what I think it means is this:

If you want to encrypt some data that gets stored persistently somewhere on your machine, rather than invent an application-specific encryption scheme for that data alone, instead use a mainstream full-partition encryption mechanism, then store the data as plaintext within said partition.

majorchord5• 2 months ago

But how is that not relying on a single encryption system?

kryogen1c• 2 months ago

From: https://infosec.exchange/@wdormann/116565129854382214

In a normal WinRE session, you have a X:\Windows\System32 directory that has a winpeshl.ini file in it
However, with the YellowKey exploit, it looks like Transactional NTFS bits on a USB Drive are able to delete the winpeshl.ini file on ANOTHER DRIVE

Interesting. I dont know about this environment - some kind of naive file handle contructing/passing? But then, why require a key press during winre reboot?

I wonder how patachable this is. The thousands of winre thumb drives are certainly out of reach; maybe the bitlocker side update the access permissions? Would it require unenc/reenc?

Seems like lots more to follow

gruez5• 2 months ago

The thousands of winre thumb drives are certainly out of reach; maybe the bitlocker side update the access permissions? Would it require unenc/reenc?

The part that isn't mentioned is that the win re is privileged because windows stores a decryption key in the TPM that allows win re to decrypt the disk even without the recovery key. That's why the attack requires win re in the first place, rather than booting into an ubuntu live cd or whatever. This also means you don't have to patch all the winRE thumbdrives out there because their secureboot signatures can simply be revoked, meaning they can't pass TPM validation anymore, therefore they won't be able to decrypt any disks.

steve1977• 2 months ago

Then I guess it is fair to call this a backdoor indeed.

bri3d4• 2 months ago

This also means you don't have to patch all the winRE thumbdrives out there because their secureboot signatures can simply be revoked, meaning they can't pass TPM validation anymore, therefore they won't be able to decrypt any disks.

WinRE runs internally, not from a thumb drive, which is why the bootloader will unseal the disk for it (just like if you have a systemd recovery set up on a Linux distribution). It doesn't have a separate key or anything, it's just allowed to use the "main" one, by design. Microsoft just need to patch the WinRE partition in a normal Windows Update to fix the NTFS transaction log driver; no Secure Boot revocation or TPM-related changes are necessary (which is good for them, because _that_ would be a disaster).

By and large this whole thing is orthogonal to BitLocker overall; boot-time unsealed BitLocker is vulnerable to any post-bootloader auth bypass by design, and this is a goofy post-bootloader auth bypass bug.

layer8• 2 months ago

Better writeup: https://infosec.exchange/@wdormann/116565129854382214

The published exploit doesn’t affect Bitlocker with a PIN, without which Bitlocker isn’t secure anyway. The original author claims they have an exploit that also works with a PIN, but hasn’t provided any proof of that.

anal_reactor• 2 months ago

Assuming that the PIN version claim is true, it's interesting to think why they would've released a nerfed useless version rather than the PIN version. I have some ideas but they're completely baseless.

qingcharles2• 2 months ago

And there is a level above PIN with Bitlocker too, you can have a USB stick with a key on it which you use only during boot. I would imagine that is secure from this attack as the data isn't even stored on the device (I hope).

briffle• 2 months ago

Does your company require the pin? Or more importantly, does the company that your company pays for Cyber insurance require the pin?

I have never seen a company where they require the pin for bitlocker.

elictronic• 2 months ago

It is a mandatory requirement for many Department of Defense Contractors. It matters what systems your company interacts with here creating the requirement. The bigger ones just mandate it to save headaches.

peapicker• 2 months ago

My employer does, and 10 digits. (very large software company)

motohagiography3• 2 months ago

The real problem with a Bitlocker backdoor or weakness is that when a laptop gets stolen or lost, in most regulated organizations, the criteria for legally declaring and disclosing a breach pivots on whether it was protected by disk encryption.

If it's a backdoor, that's a serious fraud against their customers.

bigyabai2• 2 months ago

This doesn't make much sense. Almost every single organization using Bitlocker knows that it's backdoored. It's like Push Notifications or SMS, warrantless surveillance is the norm and you don't get to opt-out. Nobody's IT department is waking up in cold sweats at the idea of the Fed stealing their data, it's part and parcel with using Windows services.

If you really think this will be prosecuted as fraud, then you'll be shocked by how American courts handle these sorts of things.

motohagiography3• 2 months ago

if you have ever dealt with a regulated institution, they have an obligation to publicly report lost and stolen devices that contain PII/PHI as a breach, and the people whose data was on the device must be notified. It's a huge deal that has board level involvement when it occurs.

The ONLY control that mitigates this risk is disk encryption, and it is perniciously misleading to ship a sabotaged product on which these legally consequential decisions get made around the world- based on the specific assurance the product is designed and marketed to provide.

If true, it is a specific outrage against the laws of several countries, medical and other research ethics, public health, and the social contracts people have with their institutions. If MS is given impunity for this, a lot of regulation is not worth the paper it is written on.

before arguing further, I recommend looking at the breach notification sections of the laws in these major economies: https://www.dlapiperdataprotection.com/

lifis• 2 months ago

Seems bullshit, apparently it only works with TPM-only mode, which is obviously insecure (it relies on neither the OS nor the hardware being exploitable, on a random Windows PC...), and not worth building a backdoor for.

The way one would backdoor something like Bitlocker is to encrypt the disk encryption key with a (post-quantum) public key for which only the backdoor owner has the private key for, and then put it on a place on disk that is unused by the filesystem.

polar• 2 months ago

Previous discussion: https://news.ycombinator.com/item?id=48130519

tamimio• 2 months ago

You should always assume that US/european corporate protections are backdoored, now MS, a couple days ago we knew about whatsapp, and I would also include all corporate “secure or encrypted” promises, so I would warn against signal, proton, and the likes. This is the work of NSA, providing a “secure” platforms and push it everywhere to get adopted, providing false sense of security, while depreciating the none bugged ones, few weeks ago verascript developer -Mounir Idrassi- complained about having their account blocked, same with wireguard facing similar issues, and if you find it hard to believe, GPG author -Zimmerman- was harassed by the gov because he wrote the encryption and encryption was considered munition, so he was exporting munition!

pregnenolone2• 2 months ago

Lots and lots of smattering around here. If anything, this is a secure boot flaw (and partially TPM), but that is a separate conversation. Also, it's been known for years that TPM based encryption should always be protected with a PIN for truly sensitive data: https://learn.microsoft.com/en-us/windows/security/operating...

The author claims to be able to bypass TPM + PIN protection, but I seriously doubt it because that would require breaking or exploiting the TPM itself. Perhaps the author was referring to existing fTPM flaws but even then, brute-forcing the PIN would still be required because on BitLocker, the wrapped VMEK depends on the PIN, which brings me to the "backdoor" topic. As I have already mentioned, exploits have been found in AMD fTPMs in the past (https://arxiv.org/abs/2304.14717). This flaw is particularly severe on Linux/cryptenroll because the TPM returns the actual FVEK, unlike BitLocker, where the VMEK itself depends on the PIN. This cryptenroll flaw has been known for years and remains unfixed on cryptenroll (https://github.com/systemd/systemd/pull/27502). Yet, I see no one yelling and crying "backdoor", or accusing Lennart of being compromised. Cryptography, especially when combined with hardware security, is inherently not easy — and people make mistakes.

utopiah• 2 months ago

Right, but proprietary software is still consider a serious option for security and privacy? What a joke.

bzmrgonz• 2 months ago

This is why I have trust issues with anything Microsoft. They keep burning bridges... And well, lots of Corporations keep trusting them. I guess they deserve each other.

ChrisArchitect• 2 months ago

[dupe] 3 days ago OP

https://news.ycombinator.com/item?id=48129789

https://news.ycombinator.com/item?id=48114997

https://news.ycombinator.com/item?id=48130519

fortran773• 2 months ago

This is a serious bug! I've just enabled TPM+PIN on all my Windows Machines (you need a PIN before the boot sequence starts) and enabled BIOS PINs (though those are easily circumvented) and Secure Boot (again, you can get a signed WinRE and still to this exploit). The TPM+PIN setting has no PoC, but the creator hints that it's possible even with this....

SilverElfin• 2 months ago

Does this mean every corporate windows laptop can basically be exploited to extract confidential information?

tavavex• 2 months ago

Only if:

- The device isn't PIN-protected (doesn't ask for a Bitlocker password on startup)

- It runs a vulnerable version of Windows (apparently anything after 10 and before whatever version Microsoft will probably patch it in)

VimEscapeArtist• 2 months ago

Anyone remember “Using TrueCrypt is not secure as it may contain unfixed security issues”? ;)

Sarky• 2 months ago

Am also thinking about TrueCrypt/VeraCrypt. Most likely more secure encryption solution... Well, definitely more secure after this debacle.

Security researcher says Microsoft built a Bitlocker backdoor, releases exploit

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