Known exploited vulnerability

CVE-2020-0601

Microsoft Windows CryptoAPI Spoofing Vulnerability

What is affected

Vendor Microsoft
Product Windows
Weakness CWE-295

The vulnerability

Microsoft Windows CryptoAPI (Crypt32.dll) contains a spoofing vulnerability in the way it validates Elliptic Curve Cryptography (ECC) certificates. An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source. A successful exploit could also allow the attacker to conduct man-in-the-middle attacks and decrypt confidential information on user connections to the affected software. The vulnerability is also known under the moniker of CurveBall.

Required action

Apply updates per vendor instructions.

US federal civilian agencies were required to act by 3 May 2022 under BOD 22-01. The deadline is a compliance date, not a measure of severity — it says nothing about how dangerous the flaw is to anyone else.

Where this comes from

Every field on this page is taken from the CISA Known Exploited Vulnerabilities catalog, last synced 12 Nov 2026, 21:26. Nothing here is our own assessment. For the technical scoring, see the NVD record below.

NVD record ↗ CVE.org record ↗

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