CVE-2020-0601
Published: November 3, 2021
Official Description
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.
CISA KEV Advisory
Microsoft Windows CryptoAPI Spoofing 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.
Apply updates per vendor instructions.
Risk Analysis
Microsoft Windows CryptoAPI (Crypt32.dll) contains a spoofing vulnerability that affects how it validates Elliptic Curve Cryptography (ECC) certificates. An attacker could use this to sign malicious executables with spoofed certificates, making them appear legitimate, or conduct man-in-the-middle attacks. The high EPSS score of 0.94093 indicates a high probability of exploitation.
This vulnerability is actively exploited in the wild and is listed in CISA's KEV catalog, confirming its use by threat actors. It can be exploited remotely.
Apply the latest security updates for Microsoft Windows to patch the CryptoAPI vulnerability and prevent certificate spoofing attacks.
Technical Analysis
CVE-2020-0601 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2020-0601 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-0601 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1