CVE-2024-27918: Github.com/coder/coder/v2 Coder's OIDC Authentication Allows Email Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7cc2-r658-7xpf",
  "modified" : "2024-03-21T18:29:31Z",
  "published" : "2024-03-04T20:45:36Z",
  "aliases" : [ "CVE-2024-27918" ],
  "summary" : "Coder's OIDC authentication allows email with partially matching domain to register",
  "details" : "### Summary\nA vulnerability in Coder's OIDC authentication could allow an attacker to bypass the `CODER_OIDC_EMAIL_DOMAIN` verification and create an account with an email not in the allowlist. Deployments are only affected if the OIDC provider allows users to create accounts on the provider (such as public providers like `google.com`).\n\n### Details\nDuring OIDC registration, the user's email was improperly validated against the allowed `CODER_OIDC_EMAIL_DOMAIN`s. This could allow a user with a domain that only partially matched an allowed domain to successfully login or register (e.g. `user@exploitcorp.com` would match the allowed domain `corp.com`).\n\nAn attacker could register a domain name that exploited this vulnerability and register on a Coder instance with a public OIDC provider.\n\n### Impact\nCoder instances with OIDC enabled and protected by the `CODER_OIDC_EMAIL_DOMAIN` configuration.\n\nCoder instances using a private OIDC provider are not affected, as arbitrary users cannot register through a private OIDC provider without first having an account on the provider.\n\nPublic OIDC providers (such as `google.com` without permitted domains set on the OAuth2 App) are impacted.\n\nGitHub authentication and external authentication are not impacted.\n\n### Was my deployment impacted?\nTo check if your deployment was exploited:\n- View the audit log on your deployment for unexpected registered users (using the `action:register` filter)\n- Check the users list for unexpected users\n    - Users created via this exploit will have a domain that ends with one of the allowed domains but doesn’t fully match (e.g. `@exploitcorp.com` instead of `@corp.com`)\n\n### Patched Versions\nThis vulnerability is remedied in\n- v2.8.4\n- v2.7.3\n- v2.6.1\n\nAll versions prior to these patches are affected by the vulnerability. **It is recommended that customers upgrade their deployments as soon as possible if they are utilizing OIDC authentication with the `CODER_OIDC_EMAIL_DOMAIN` setting.**\n\n### Thanks\n- https://github.com/arcz\n- https://www.trailofbits.com\n\n### References\nhttps://github.com/coder/coder/security/advisories/GHSA-7cc2-r658-7xpf\nhttps://github.com/coder/coder/commit/4439a920e454a82565e445e4376c669e3b89591c\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-27918",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.8.0"
      }, {
        "fixed" : "2.8.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.7.0"
      }, {
        "fixed" : "2.7.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.6.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.27.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/security/advisories/GHSA-7cc2-r658-7xpf"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-27918"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/commit/1171ce7add017481d28441575024209ac160ecb0"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/commit/2ba84911f8b02605e5958d5e4a2fe3979ec50b31"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/commit/2d37eb42e7db656e343fe1f36de5ab1a1a62f4fb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/commit/4439a920e454a82565e445e4376c669e3b89591c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/coder/coder"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-03-04T20:45:36Z",
    "nvd_published_at" : "2024-03-21T02:52:20Z"
  }
}