CVE-2020-0601: Windows CryptoAPI Vulnerability. (CurveBall/ChainOfFools)# CurveBall ([CVE-2020-0601](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0601)) - PoC
CVE-2020-0601: Also known as CurveBall or ChainOffFools, is a vulnerability in the Microsoft CryptoApi (specificly in Crypt32.dll) where elliptic curve signatures (ECDSA) of certificates is not correctly verified.
There is a very nice blog post [here](https://research.kudelskisecurity.com/2020/01/15/cve-2020-0601-the-chainoffools-attack-explained-with-poc/) which explains the issue very neatly.
*This should only be used for educational and researching purposes!*
## How to
Provide the console application with the path to an elliptic curve certificate.
```
CurveBall.exe 'PathToCA.cer'
```
The program will output a .p12 file contaning a certificate with the same public key and serial number as the original, including a key.
The key and cert can be extracted from the .p12 by using openssl with the following commands
```
openssl pkcs12 -in Rogue.p12 -nocerts -out CA.key
```
and
```
openssl pkcs12 -in Rogue.p12 -clcerts -nokeys -out CA.cer
```
NOTE: Default password is 'Test1234'.
[4.0K] /data/pocs/8ca8bbb583cc7cce5747d6a6dc4b3b9568818e25
├── [4.0K] CurveBall
│ ├── [ 282] CurveBall.csproj
│ ├── [4.0K] Extensions
│ │ └── [ 847] X509CertificateExtensions.cs
│ └── [4.3K] Program.cs
├── [ 782] CurveBall.sln
├── [ 11K] LICENSE
└── [1.1K] README.md
2 directories, 6 files