CVE-2021-22573: Google oauth client Google-oauth-java-client Improperly Verifies Cryptographic Signature Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hw42-3568-wj87",
  "modified" : "2024-04-09T15:11:24Z",
  "published" : "2024-04-09T15:11:24Z",
  "aliases" : [ "CVE-2021-22573" ],
  "summary" : "google-oauth-java-client improperly verifies cryptographic signature",
  "details" : "### Summary\nThe vulnerability impacts only users of the `IdTokenVerifier` class. The verify method in `IdTokenVerifier` does not validate the signature before verifying the claims (e.g., iss, aud, etc.). Signature verification makes sure that the token's payload comes from valid provider, not from someone else.\n\nAn attacker can provide a compromised token with modified payload like email or phone number. The token will pass the validation by the library. Once verified, modified payload can be used by the application. \n\nIf the application sends verified `IdToken` to other service as is like for auth - the risk is low, because the backend of the service is expected to check the signature and fail the request. \n\nReporter: [Tamjid al Rahat](https://github.com/tamjidrahat), contributor\n\n### Patches\nThe issue was fixed in the 1.33.3 version of the library\n\n### Proof of Concept\nTo reproduce, one needs to call the verify function with an IdToken instance that contains a malformed signature to successfully bypass the checks inside the verify function.\n\n```\n  /** A default http transport factory for testing */\n  static class DefaultHttpTransportFactory implements HttpTransportFactory {\n    public HttpTransport create() {\n      return new NetHttpTransport();\n    }\n  }\n\n// The below token has some modified bits in the signature\n private static final String SERVICE_ACCOUNT_RS256_TOKEN_BAD_SIGNATURE =    \n\"eyJhbGciOiJSUzI1NiIsImtpZCI6IjJlZjc3YjM4YTFiMDM3MDQ4NzA0MzkxNmFjYmYyN2Q3NG\" +\n\"VkZDA4YjEiLCJ0eXAiOiJKV1QifQ.eyJhdWQiOiJodHRwczovL2V4YW1wbGUuY29tL2F1ZGllbm\" +\n\"NlIiwiZXhwIjoxNTg3NjMwNTQzLCJpYXQiOjE1ODc2MjY5NDMsImlzcyI6InNvbWUgaXNzdWVy\" +\n\"Iiwic3ViIjoic29tZSBzdWJqZWN0In0.gGOQW0qQgs4jGUmCsgRV83RqsJLaEy89-ZOG6p1u0Y26\" +\n\"FyY06b6Odgd7xXLsSTiiSnch62dl0Lfi9D0x2ByxvsGOCbovmBl2ZZ0zHr1wpc4N0XS9lMUq5RJ\" + \n\"QbonDibxXG4nC2zroDfvD0h7i-L8KMXeJb9pYwW7LkmrM_YwYfJnWnZ4bpcsDjojmPeUBlACg7tjjOgBFby\" +\n\"QZvUtaERJwSRlaWibvNjof7eCVfZChE0PwBpZc_cGqSqKXv544L4ttqdCnm0NjqrTATXwC4gYx\" + \n\"ruevkjHfYI5ojcQmXoWDJJ0-_jzfyPE4MFFdCFgzLgnfIOwe5ve0MtquKuv2O0pgvg\";\n\nIdTokenVerifier tokenVerifier =\n        new IdTokenVerifier.Builder()\n            .setClock(clock)\n            .setCertificatesLocation(\"https://www.googleapis.com/robot/v1/metadata/x509/integration-tests%40chingor-test.iam.gserviceaccount.com\")\n            .setHttpTransportFactory(new DefaultHttpTransportFactory())\n            .build();\n\n// verification will return true despite modified signature for versions <1.33.3\ntokenVerifier.verify(IdToken.parse(GsonFactory.getDefaultInstance(), SERVICE_ACCOUNT_RS256_TOKEN_BAD_SIGNATURE));\n\n```\n\n### Remediation and Mitigation\nUpdate to the version 1.33.3 or higher \n\nIf the library used indirectly or cannot be updated for any reason you can use similar IdToken verifiers provided by Google that already has signature verification. For example: \n[google-auth-library-java](https://github.com/googleapis/google-auth-library-java/blob/main/oauth2_http/java/com/google/auth/oauth2/TokenVerifier.java)\n[google-api-java-client](https://github.com/googleapis/google-api-java-client/blob/main/google-api-client/src/main/java/com/google/api/client/googleapis/auth/oauth2/GoogleIdTokenVerifier.java)\n\n### Timeline\nDate reported: 12 Dec 2021\nDate fixed: 13 Apr 2022\nDate disclosed: 2 May 2022\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [google-oauth-java-client](https://github.com/googleapis/google-oauth-java-client) repo",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.google.oauth-client:google-oauth-client"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.16.0-rc"
      }, {
        "fixed" : "1.33.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/googleapis/google-oauth-java-client/security/advisories/GHSA-hw42-3568-wj87"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-22573"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/googleapis/google-oauth-java-client/pull/872"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/googleapis/google-oauth-java-client/commit/c634ad4e31cac322bb1aa8a9feb0569749011bf0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/googleapis/google-oauth-java-client"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-347" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-09T15:11:24Z",
    "nvd_published_at" : null
  }
}