ECC Curveball - Cryptoapi.dll ECC certificate spoofing

Metadata

Release date	14.01.2020
Author	? Unknown ?
Classification	Certificate spoofing / MITM
Patched	yes
Patch date	14.01.2020
First patched system version	10.0.18363.9135 (19h1_release_xbox_dev_2002.200219-1515)
Source	https://nvd.nist.gov/vuln/detail/CVE-2020-0601 / https://github.com/saleemrashid/badecparams
Download	XboxOneResearch GIT

Info

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'.

(Source: https://nvd.nist.gov/vuln/detail/CVE-2020-0601)

Prerequisites

Xbox console running Windows 10.

• First vulnerable version: 10.0.10586.1006 (th2_xbox_rel_1510.151107-2322) fre

  • Released: 2015-11-12

• Last vulnerable version: 10.0.18363.8124 (19h1_release_xbox_dev_1911.191202-1836)

  • Released: 2019-12-09

Instructions

1. Setup DNS server or port forwarding that routes (SSL) Xbox traffic to the MITM host
2. Adjust certificate validity timespan in certificate generation script
3. Generate spoofed certificate
4. Serve spoofed certificate via httpd.py

Alternatively, a mitm-proxy software can be used.

Authors: tuxuser