It's been reported that Windows Defender can detect and report on malicious certificates:
https://twitter.com/AmitaiTechie/status/1217156973268893696
Of course, that relies on not having Defender disabled by an alternate product.
Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
81–90 of 235 posts
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#82Earlier quoted context omitted.
They have probably done that for a while (this is the first public attribution , not the first disclosure); but they are now blowing their trumpet because they need some good PR. Why? Snowden.
Much more likely the bad reaction to Eternal Blue.
EternalBlue would have not received that much coverage had it not happened after Snowden proved that the American public cannot trust the agency. They had been dragged to the foreground before without repercussions, because reactions were limited to the IT world. Snowden made it a general-public issue, and now they are forced to to shape up.
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#83None of these links describe how the exploit works. I found this: https://media.defense.gov/2020/Jan/14/2002234275/-1/-1/0/CSA... So based on my limited understanding: 1. The certificates have a place for defining curve parameters. 2. The attacker specifies their own parameters so that they match the start of a standard curve but choose the rest of the parameters themselves. With the right ECC math they are able to g…
A lot of what happens at MSRC is auditing for related vulnerabilities - trying to find any place where similar code might make the same mistake. In this case, since roll-your-own cryptography is so strongly discouraged (with good reason), I suspect that there won't be as many places to audit
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#84Oh great. Mozilla just added last week an option for entreprises to enable trusting of system certificates on Windows. See Firefox 72.0 release notes: https://www.mozilla.org/en-US/firefox/72.0/releasenotes/
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#85Earlier quoted context omitted.
They are paid to collect intelligence for the benefit of the american people, not american companies. Luckily citizens united hasn't stretched that far.
Their mission also explicitly includes information assurance: Mission Statement The National Security Agency/Central Security Service (NSA/CSS) leads the U.S. Government in cryptology that encompasses both signals intelligence (SIGINT) and information assurance (now referred to as cybersecurity) products and services, and enables computer network operations (CNO) in order to gain a decision advantage for the Nation a…
They've got to balance both roles.
IIRC, in earlier times the government didn't use as much COTS stuff, and civilian computer systems weren't so critical, so the roles were easier to separate. The NSA developed whole series of secret encryption algorithms for the exclusive use of the government/military, and civilian algorithms weren't approved to secure classified communications.
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#86Earlier quoted context omitted.
The tweet* from the call with reporters - a cynical person might think instead that NSA thought that with the similarity to the LE and FF flaws it was not much longer before a hostile actor would find this crypt.dll flaw so it was time to notify MS. * https://twitter.com/briankrebs/status/1217125030452256768
Didn't the FBI or NSA push for flawed Elliptical Curve Crypto in the past? Could be the knew about it for a while and had milked it hard until they caught someone else using it. Or like the parent said, previously discovered flaws meant that someone might catch this one, too.
There is no evidence that US push flawed curves.
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#87Earlier quoted context omitted.
The important part might be just how hard it is to come-up with G'.
As you can see, it's not at all hard.
Yes if it's that it's not even particularly computationally expensive. I hope that's not the crux of the flaw.
edit: seems to be this bug letting attacker specify params https://twitter.com/thracky/status/1217175743316348929
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#88From a conversation with Thomas Pornin, a plausible explanation given the details provided in the DoD advisory: Given an ECDSA signature and control over the curve domain parameters, it's straightforward to create a second private key that matches the original public key, without knowledge of the original signing private key. Here's how: To start with, you need to understand a little bit about how curve cryptography…
I hope that the actual vulnerability is far more complicated. If we can't even get crypto libraries right (where you'd hope most of the formal verification folks are), then there's not much hope of security for the rest of the industry.
I'm normally not much of a pessimist but things like this really make me wish we could just burn all the things and start over.
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#89Earlier quoted context omitted.
The tweet* from the call with reporters - a cynical person might think instead that NSA thought that with the similarity to the LE and FF flaws it was not much longer before a hostile actor would find this crypt.dll flaw so it was time to notify MS. * https://twitter.com/briankrebs/status/1217125030452256768
Didn't the FBI or NSA push for flawed Elliptical Curve Crypto in the past? Could be the knew about it for a while and had milked it hard until they caught someone else using it. Or like the parent said, previously discovered flaws meant that someone might catch this one, too.
It was Dual EC DRBG, a prng
Re: Patch Critical Cryptographic Vulnerability in Microsoft Windows [pdf]
#90Earlier quoted context omitted.
That this exploit can be used to spoof the Windows Update system is a big yikes. You can’t necessarily trust today’s update itself.
That depends on whether Windows Update is using ECC certificates. A quick scan of my Windows 10 trusted root certificate store shows almost exclusively RSA based certificates, so I’d guess 80% odds that Windows Update itself isn’t affected.
It may still be affected, the system may accept a bad ECC cert and override the RSA cert.