Exploiting the Windows CryptoAPI Vulnerability

Summary: The NSA announced a critical vulnerability in certificate validation on Windows 10 and Windows Server 2016/2019, where Crypt32.dll fails to check that elliptic curve parameters in a supplied root certificate match those Microsoft knows. For cached root certificates using elliptic curve cryptography, Windows skips parameter validation when the public key matches the cache, letting an attacker set a generator tied to a private key they control and forge signatures for TLS, code, files, and email.
Bottom line: Trail of Bits calls the flaw absolutely devastating and says all Windows 10 systems must be patched immediately, and public exploit code became available the same day it published. Until patched, an attacker can present a forged root certificate in the TLS chain and issue valid certificates for almost any website.

Read the original at Trail of Bits Blog ↗