WoSign, Why Don't You Just Fly to the Sky!

This post is automatically translated with LLM. The translation content has NOT been reviewed and may contain errors.

Just saw on V2EX that someone exploited a vulnerability in WoSign's certificate issuance system to successfully issue a certificate for GitHub's main domain.

https://crt.sh/?id=29647048

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            5d:8f:2b:91:ef:b8:dd:65:af:4c:c1:2b:15:ef:4b:6e
    Signature Algorithm: sha256WithRSAEncryption
        Issuer:
            commonName                = WoSign CA Free SSL Certificate G2
            organizationName          = WoSign CA Limited
            countryName               = CN
        Validity
            Not Before: Jun 10 05:42:44 2015 GMT
            Not After : Jun 10 06:03:35 2018 GMT
        Subject:
            commonName                = schrauger.github.io
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    00:e4:3b:a1:76:73:3c:b1:62:8d:53:6d:ef:a8:e9:
                    5b:9e:0e:15:63:e6:57:ac:cc:31:b3:48:2b:01:74:
                    ae:d8:7d:1c:6b:ed:2a:40:45:36:62:83:ac:d7:a5:
                    80:9c:21:88:dc:ec:4d:ae:35:5d:65:e6:95:ee:81:
                    7a:1f:b5:a7:e9:19:f8:7a:42:ff:dc:b4:71:63:ce:
                    3c:70:6f:89:54:af:57:de:27:bb:79:07:54:44:68:
                    ee:1c:7e:14:d9:eb:bc:4e:99:52:f6:b5:34:30:2c:
                    38:63:7b:95:8a:ea:54:7e:d5:4b:f0:1d:73:3b:03:
                    ea:12:2d:8a:3c:ea:f2:f1:04:5a:1b:8b:cf:3e:c9:
                    98:e6:2a:69:53:67:61:d0:6b:79:33:b6:08:3a:be:
                    dd:16:d6:02:ab:f2:6d:e0:02:be:f2:d9:13:6b:08:
                    b7:f2:de:fa:79:d1:4c:39:f8:bb:e5:18:89:f2:2b:
                    b6:df:59:54:9e:8a:48:0e:06:fb:eb:ad:e0:2a:b5:
                    0a:e8:51:45:bc:ac:51:65:cf:69:de:64:8f:30:e0:
                    d7:c6:c1:fd:30:1d:99:ea:7c:3d:d4:f6:bb:87:c9:
                    dd:f0:e4:74:4e:92:2d:27:5e:8c:fc:42:79:7f:59:
                    7c:f4:40:71:de:c3:b8:6e:a9:21:7e:8f:8c:7d:2c:
                    2c:85
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Key Usage:
                Digital Signature, Key Encipherment
            X509v3 Extended Key Usage:
                TLS Web Client Authentication, TLS Web Server Authentication
            X509v3 Basic Constraints:
                CA:FALSE
            X509v3 Subject Key Identifier:
                F7:8A:D1:06:8A:4B:6F:1F:B2:BA:39:A6:03:D7:C7:61:E5:14:0C:05
            X509v3 Authority Key Identifier:
                keyid:D2:A7:16:20:7C:AF:D9:95:9E:EB:43:0A:19:F2:E0:B9:74:0E:A8:C7

            Authority Information Access:
                OCSP - URI:http://ocsp6.wosign.com/ca6/server1/free
                CA Issuers - URI:http://aia6.wosign.com/ca6.server1.free.cer

            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crls6.wosign.com/ca6-server1-free.crl

            X509v3 Subject Alternative Name:
                DNS:schrauger.github.io
                DNS:schrauger.github.com
                DNS:github.io
                DNS:github.com
                DNS:www.github.io
            X509v3 Certificate Policies:
                Policy: 2.23.140.1.2.1
                Policy: 1.3.6.1.4.1.36305.6.1.2.2.1
                  CPS: http://www.wosign.com/policy/

    Signature Algorithm: sha256WithRSAEncryption
         36:1f:74:a6:b4:98:b6:95:b3:7e:d1:c7:91:0c:5a:35:bd:05:
         00:3f:93:c2:1d:72:e0:b9:36:32:a3:d8:0d:91:53:f5:f9:f6:
         30:38:d3:06:02:7a:30:aa:90:38:aa:b7:aa:06:c9:7b:9e:4c:
         21:67:70:fd:c2:16:a3:c1:b0:73:ae:e5:b9:a6:e8:d7:f1:76:
         ce:a4:71:be:f0:1a:81:3c:ee:7a:8e:7a:1e:b7:5d:28:89:bf:
         62:c2:1d:75:47:b1:e5:51:95:48:f1:d5:1a:a4:71:09:c5:59:
         79:dc:04:88:3e:40:c2:3d:b6:92:ee:4d:67:61:7a:c8:42:32:
         e2:83:6a:0d:98:a9:69:71:12:f3:d7:f2:36:d5:7f:fa:b3:fd:
         1e:97:16:ab:81:08:d1:f5:67:11:7a:73:3d:5d:79:35:f5:57:
         56:ed:52:5d:86:af:07:5b:af:bd:62:87:c7:4e:c5:4f:59:fe:
         1c:c6:35:ef:36:3c:b7:43:e8:b6:b1:b8:d9:1e:a2:fc:7c:a9:
         f2:98:ff:3d:76:f2:75:0d:13:e4:f8:cd:f8:c5:f6:c0:60:06:
         9c:3a:13:e0:ff:86:5a:14:a6:6e:2e:e6:ca:10:01:c0:d9:34:
         a2:07:ab:0a:ba:19:79:c0:9c:b0:c5:97:c4:b4:64:12:c3:ce:
         e4:c1:fd:ae