NSA discovers huge security flaw in Microsoft’s Windows 10  - Page 1
Forum section: electronics / general

author: Black Phoenix
author_rank: Super Contributor
timestamp: January 16, 2020, 04:10:41 am
content: https://nypost.com/2020/01/15/nsa-discovers-huge-security-flaw-in-microsofts-windows-10/QuoteQuoteYes I totally believe in you NSA...

author: ataradov
author_rank: Super Contributor
timestamp: January 16, 2020, 04:32:48 am
content: NSA was using this for ages, and then they probably realized that some other nation is aware of the issue too, so time to report.

author: Stray Electron
author_rank: Super Contributor
timestamp: January 16, 2020, 04:53:15 am
content: I don't know who I trust less, MicroSoft or the NSA.

author: Black Phoenix
author_rank: Super Contributor
timestamp: January 16, 2020, 05:55:07 am
content: Quote from: ataradov on January 16, 2020, 04:32:48 amOr being someone in the Conspiracy theory field, they found a way of using it even while patch, so let's give some sense of security while we keep doing what we do...

author: Berni
author_rank: Super Contributor
timestamp: January 16, 2020, 07:18:52 am
content: QuoteThis does not make any sense. So the exploit is to do with being able to code sign an executable without having the appropriate keys. Not too worried about that since how many people look at the thing anyway.But how do you go from that to "man in the middle attacks" and "decrypting confidential information"? Are they just making things up or is this another case of the press having no idea what they are talking about and just throwing technical sounding words.

author: Electro Detective
author_rank: Super Contributor
timestamp: January 16, 2020, 08:53:47 am
content: another publicity stunt..??but wait, aren't both groups Linux users?

author: bd139
author_rank: Super Contributor
timestamp: January 16, 2020, 09:40:30 am
content: Quote from: Berni on January 16, 2020, 07:18:52 amNo it is exactly right. It's the crypto library that is flawed. This is used for both code signing and TLS negotiation. Thus you can forge a certificate and leverage an existing trust relationship easily. That can be used to set up an insecure TLS connection to MITM and obtain data or generated a code signing certificate that bypasses prompts.With these things you have to ignore the dumbed down press and go straight to the source:https://media.defense.gov/2020/Jan/14/2002234275/-1/-1/0/CSA-WINDOWS-10-CRYPT-LIB-20190114.PDFFrom my understanding what they discovered was elliptic curve parameters could be specified in the certificate which were not validated against standard curves. That allows intentionally weak parameters to be injected into the certificate to decrease certificate generation effort to something reasonable (seconds instead of billions of years).And yes NSA have probably been using this for months. It probably only got released after it was no longer useful against their adversaries or they have another set of exploits lined up.

author: Berni
author_rank: Super Contributor
timestamp: January 16, 2020, 12:13:56 pm
content: Ah yeah makes more sense now.But yeah im pretty sure the NSA has been exploiting this for a while before revealing it. Released it probably because they noticed someone else using it.Also the fact that this cypto library vulnerability suddenly appeared in Win 10 and does not affect older ones makes it seam like it might have been introduced on purpose.Do web browsers also use this library or bring there own?

author: bd139
author_rank: Super Contributor
timestamp: January 16, 2020, 12:32:06 pm
content: Chrome and firefox bring their own. IE and Edge reuse Windows CryptoAPI. I'm not sure what the new Edge version (based on Chrome) uses

author: Berni
author_rank: Super Contributor
timestamp: January 16, 2020, 12:39:54 pm
content: Quote from: bd139 on January 16, 2020, 12:32:06 pmAh yes that is a BIG issue then. I thought that crypto library was mostly used to encrypt the win 10 telemetry crap and other built in things.

author: tombi
author_rank: Regular Contributor
timestamp: January 16, 2020, 03:09:52 pm
content: Kind-of - I think it is basically the Vaudenay attack.https://lasec.epfl.ch/pub/lasec/doc/Vau04b.pdfI think you can include curve parameters in the signature algorithm identifier. It stupidly doesn't check these match the curve specified in the issuer cert's public key. It happily verifies the signature using the specified parameters and if it checks out the code is happy. It should be checking they match the curve specified in the algorithm identifier of the issuer's public key.The thing is you can find a set of parameters that matches the issuer public key and the signature without knowing the issuer's private key. Hence you can make your own certificate that will checkout as signed by something trustworthy.Forgive me if I have mangled this a bit but this is my understanding at the moment.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: January 16, 2020, 03:19:42 pm
content: Quote from: ataradov on January 16, 2020, 04:32:48 amVladimir Putin!"Microsoft Wins $10 Billion Department of Defense Cloud Contract"https://nypost.com/2019/10/28/pentagon-hands-microsoft-10b-war-cloud-deal-snubs-amazon/No worries!

author: bd139
author_rank: Super Contributor
timestamp: January 16, 2020, 07:19:37 pm
content: Technical information on the vulnerabilityhttps://blog.trailofbits.com/2020/01/16/exploiting-the-windows-cryptoapi-vulnerability/