There’s a working Proof of Concept for the “ChainOfFools” CVE-2020-0601 Crypto API bug — but it isn’t as bad as you think

[Karlston]

There’s a working Proof of Concept for the “ChainOfFools” CVE-2020-0601 Crypto API bug — but it isn’t as bad as you think

Long story short, Yolan Ronmailler has posted a working Proof of Concept for NSA’s CVE-2020-0601 Crypt32 bug. The code is available on Github.

 

There’s no question the code works — but it has a prerequisite. In order to get bitten by the security hole, you have to first visit a specific site. That site will load a security certificate that’s instrumental in making the PoC code work.

 

That severely limits the threat, eh?

 

Here’s how Ronmailler puts it:

In the end, please keep in mind that such a vulnerability is not at risk of being exploited by script kiddies or ransomware. While it is still a big problem because it could have allowed a Man-in-the-Middle attack against any website, you would need to face an adversary that owns the network on which you operate, which is possible for nation-state adversaries, but less so for a script kiddie. This is why we are releasing this PoC, the exploitability of this vulnerability is not good enough to lead to a sudden ransomware threat (unlike the one we had with Wannacry). This is also probably why the NSA decided not to weaponize their finding, but to rather disclose it: for them it is best to have the USA patched rather than to keep it and take the risk of it being used against the USA, as the attack surface is so vast.

Which ties up many loose ends.

 

Looks like Kevin Beaumont is right: There’s certainly a security hole here, but it would be very difficult to turn it into a widespread attack. In order for it to work, the victim first has to visit a site that has a clean copy of the certificate that the attacker has subverted, and then visit the site with the subverted certificate. Unless the attacker has full control over your network, the chances of that happening are slim indeed.

 

(Saleem Rashid showed yesterday that the clean-before-dirty approach is a requirement for the Chrome browser, but Chrome throws a NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED. Firefox isn’t vulnerable.)

 

As I said in the Computerworld article, it’s a long way from a third-degree polynomial to working ransomware.

 

We’re still at MS-DEFCON 2.

 

UPDATE: Kevin Beaumont has a revised recommendation:

 

 

 

Source: There’s a working Proof of Concept for the “ChainOfFools” CVE-2020-0601 Crypto API bug — but it isn’t as bad as you think (AskWoody - Woody Leonhard)

[steven36]

51 minutes ago, Karlston said:

This is also probably why the NSA decided not to weaponize their finding, but to rather disclose it: for them it is best to have the USA patched rather than to keep it and take the risk of it being used against the USA, as the attack surface is so vast.

This is just guessing .  NSA  moved away from Elliptic Curve Cryptography in 2015 . They knew  it  was a problem every since  2015  and they waited to tell 2019 to tell Microsoft  .(patched in 2020)

 

NSA’s Divorce from ECC Causing Crypto Hand-Wringing  October 23, 2015

https://threatpost.com/nsas-divorce-from-ecc-causing-crypto-hand-wringing/115150/

 

The year Windows 10 came out with it the NSA recommended  not to use anymore only reason they would stop using something besides them have or will  compromised it.

 

They several  theories The NSA knows  quantum computing can break it so there pushing people toward RSA is one of them.

 

facts: NSA  already had this exploit no telling  how long they had  it ,  the government uses exploits  for many years  tell  they  no value to them anymore  or someone else steals it  or discloses it.   EternalBlue  , Stuxnet and Now this one is just few of them we know  about.

 

Quote

 

Given the known motivations of the NSA, and the deep involvement they had in designing and promoting SHA and its derivatives gives reasonable doubt to their benevolent credibility. Look at the amount of trouble the NSA went into to create Stuxnet. They stole digitally signed certificates from big corporations, completely undetected. If a known burglar installed your home security system, even if the security system was from a well known and trusted manufacturer would you trust that your house was actually secure while you were on vacation?

 

 

 

 

In other words  you can trust nothing the NSA  says let alone someone guessing about the NSA . The last people to leak stuff about the NSA to public  are a. in jail  b. Are in exile in Russia .

 

Fact  Security researcher Saleem Rashid "rickrolled" himself to show that the bug could be exploited in the real world to spoof security certificates on machines without Microsoft's patch. source:

https://www.techrepublic.com/article/how-a-researcher-exploited-the-windows-10-bug-patched-by-microsoft/

 

Fact there is no Researchers know why the NSA disclosed  it yet the reason  its not public and confidential .