Microsoft Windows up to Server 2019 CryptoAPI Crypt32.dll ECC Certificate certificate validation

Summaryinfo

A vulnerability marked as critical has been reported in Microsoft Windows. This affects an unknown function of the file Crypt32.dll of the component CryptoAPI. The manipulation as part of ECC Certificate leads to certificate validation. This vulnerability is uniquely identified as CVE-2020-0601. The attack is possible to be carried out remotely. Moreover, an exploit is present. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows (Operating System). It has been rated as critical. This issue affects an unknown code of the file Crypt32.dll of the component CryptoAPI. The manipulation as part of a ECC Certificate leads to a certificate validation vulnerability. Using CWE to declare the problem leads to CWE-295. The product does not validate, or incorrectly validates, a certificate. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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'.

The weakness was disclosed 01/14/2020 as confirmed security update guide (Website). It is possible to read the advisory at portal.msrc.microsoft.com. The public release has been coordinated in cooperation with Microsoft. The identification of this vulnerability is CVE-2020-0601. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details as well as a public exploit are known. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK. The advisory points out:

A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates.

The exploit is available at exploit-db.com. It is declared as attacked. We expect the 0-day to have been worth approximately $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 266278 (NewStart CGSL MAIN 6.06 : neod Multiple Vulnerabilities (NS-SA-2025-0234)), which helps to determine the existence of the flaw in a target environment. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 11/03/2021 with a due date of 05/03/2022:

Apply updates per vendor instructions.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (47933) and Tenable (266278). The entries VDB-148611, VDB-148610, VDB-148609 and VDB-148608 are pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 10
• 10 1607
• 10 1709
• 10 1803
• 10 1809
• 10 1903
• 10 1909
• Server 1803
• Server 1903
• Server 1909
• Server 2016
• Server 2019

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion