Background exploitation KEV catalog No authentication

CVE-2020-0601

Microsoft Windows CryptoAPI Spoofing Vulnerability

CheckOps priority index

8.3/10 Patch within 24 h

Severity8.1

Probability8.9

Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 89.1% higher than 99.8% of CVEs

CVSS 3.1 8.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:

Exploited for 1,826 days 03 Nov 2021

CISA due date 03 May 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

KEV catalog (CISA)03 Nov 2021
Exploited in EUVD (ENISA)03 Nov 2021
Used by ransomwareno
EPSS above 10 %89.1%
No account, over the networkyes

What to do

Fix

Update to a fixed version: 1.12.16 1.13.7

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) 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, aka 'Windows CryptoAPI Spoofing Vulnerability'.

Affected products

WindowsWindows 10 Version 1903 for 32-bit SystemsWindows Server, version 1909 (Server Core installation)Windows ServerWindows 10 Version 1909 for ARM64-based SystemsWindows 10 Version 1903 for ARM64-based SystemsWindows 10 Version 1909 for x64-based SystemsWindows 10 Version 1903 for x64-based SystemsWindows Server, version 1903 (Server Core installation)Windows 10 Version 1909 for 32-bit Systems

Affected versions

10 Version 1803 for ARM64-based Systems
unspecified
10 Version 1607 for x64-based Systems
10 for 32-bit Systems
2019
10 Version 1709 for x64-based Systems
10 for x64-based Systems
2019 (Core installation)
10 Version 1803 for 32-bit Systems
10 Version 1803 for x64-based Systems
10 Version 1809 for 32-bit Systems
10 Version 1709 for ARM64-based Systems

Weaknesses (CWE)

CWE-295

Open source packages OSV

stdlibGo · GO-2022-0535
fixed in 1.12.16, 1.13.7

Timeline

14 Jan 2020
Published
03 Nov 2021
Exploitation reported (ENISA)
03 Nov 2021
Added to the KEV catalog
03 May 2022
CISA remediation due date
26 Sept 2026
EPSS peak: 89.4%

References

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