ghsa-q9hr-j4rf-8fjc
Vulnerability from github
Published
2023-01-25 22:02
Modified
2023-02-07 21:21
Severity
9.0 (Critical) - CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Summary
JWT audience claim is not verified
Details

Impact

All versions of Argo CD starting with v1.8.2 are vulnerable to an improper authorization bug causing the API to accept certain invalid tokens.

OIDC providers include an aud (audience) claim in signed tokens. The value of that claim specifies the intended audience(s) of the token (i.e. the service or services which are meant to accept the token). Argo CD does validate that the token was signed by Argo CD's configured OIDC provider. But Argo CD does not validate the audience claim, so it will accept tokens that are not intended for Argo CD.

If Argo CD's configured OIDC provider also serves other audiences (for example, a file storage service), then Argo CD will accept a token intended for one of those other audiences. Argo CD will grant the user privileges based on the token's groups claim, even though those groups were not intended to be used by Argo CD.

This bug also increases the blast radius of a stolen token. If an attacker steals a valid token for a different audience, they can use it to access Argo CD.

Patches

A patch for this vulnerability has been released in the following Argo CD versions:

  • v2.6.0-rc5
  • v2.5.8
  • v2.4.20
  • v2.3.14

The patch introduces a new allowedAudiences to the OIDC config block. By default, the client ID is the only allowed audience. Users who want Argo CD to accept tokens intended for a different audience may use allowedAudiences to specify those audiences.

`yaml apiVersion: v1 kind: ConfigMap metadata: name: argocd-cm data: oidc.config: | name: Example allowedAudiences: - audience-1 - audience-2 - argocd-client-id # If `allowedAudiences` is non-empty, Argo CD's client ID must be explicitly added if you want to allow it.

Even though the OIDC spec requires the audience claim, some tokens may not include it. To avoid a breaking change in a patch release, versions < 2.6.0 of Argo CD will skip the audience claim check for tokens that have no audience. In versions >= 2.6.0, Argo CD will reject all tokens which do not have an audience claim. Users can opt into the old behavior by setting an option:

yaml apiVersion: v1 kind: ConfigMap metadata: name: argocd-cm data: oidc.config: | name: Example skipAudienceCheckWhenTokenHasNoAudience: true

Workarounds

There is no workaround besides upgrading.

Credits

The Argo CD team would like to express their gratitude to Vladimir Pouzanov (@farcaller) from Indeed, who discovered the issue, reported it confidentially according to our guidelines, and actively worked with the project to provide a remedy. Many thanks to Vladimir!

References

For more information

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.8.2"
            },
            {
              "fixed": "2.3.14"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.4.0"
            },
            {
              "fixed": "2.4.20"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.5.0"
            },
            {
              "fixed": "2.5.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/argoproj/argo-cd"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.0-rc1"
            },
            {
              "fixed": "2.6.0-rc5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-22482"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-01-25T22:02:52Z",
    "nvd_published_at": "2023-01-26T21:18:00Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nAll versions of Argo CD starting with v1.8.2 are vulnerable to an improper authorization bug causing the API to accept certain invalid tokens.\n\nOIDC providers include an `aud` (audience) claim in signed tokens. The value of that claim specifies the intended audience(s) of the token (i.e. the service or services which are meant to accept the token). Argo CD _does_ validate that the token was signed by Argo CD\u0027s configured OIDC provider. But Argo CD _does not_ validate the audience claim, so it will accept tokens that are not intended for Argo CD.\n\nIf Argo CD\u0027s configured OIDC provider also serves other audiences (for example, a file storage service), then Argo CD will accept a token intended for one of those other audiences. Argo CD will grant the user privileges based on the token\u0027s `groups` claim, even though those groups were not intended to be used by Argo CD.\n\nThis bug also increases the blast radius of a stolen token. If an attacker steals a valid token for a different audience, they can use it to access Argo CD.\n\n### Patches\n\nA patch for this vulnerability has been released in the following Argo CD versions:\n\n* v2.6.0-rc5\n* v2.5.8\n* v2.4.20\n* v2.3.14\n\nThe patch introduces a new `allowedAudiences` to the OIDC config block. By default, the client ID is the only allowed audience. Users who _want_ Argo CD to accept tokens intended for a different audience may use `allowedAudiences` to specify those audiences.\n\n```yaml\napiVersion: v1\nkind: ConfigMap\nmetadata:\n  name: argocd-cm\ndata:\n  oidc.config: |\n    name: Example\n    allowedAudiences:\n    - audience-1\n    - audience-2\n    - argocd-client-id  # If `allowedAudiences` is non-empty, Argo CD\u0027s client ID must be explicitly added if you want to allow it.\n``\n\nEven though [the OIDC spec requires the audience claim](https://openid.net/specs/openid-connect-core-1_0.html#IDToken), some tokens may not include it. To avoid a breaking change in a patch release, versions \u003c 2.6.0 of Argo CD will skip the audience claim check for tokens that have no audience. In versions \u003e= 2.6.0, Argo CD will reject all tokens which do not have an audience claim. Users can opt into the old behavior by setting an option:\n\n```yaml\napiVersion: v1\nkind: ConfigMap\nmetadata:\n  name: argocd-cm\ndata:\n  oidc.config: |\n    name: Example\n    skipAudienceCheckWhenTokenHasNoAudience: true\n```\n\n### Workarounds\n\nThere is no workaround besides upgrading.\n\n### Credits \n\nThe Argo CD team would like to express their gratitude to Vladimir Pouzanov (@farcaller) from Indeed, who discovered the issue, reported it confidentially according to our [guidelines](https://github.com/argoproj/argo-cd/blob/master/SECURITY.md#reporting-a-vulnerability), and actively worked with the project to provide a remedy. Many thanks to Vladimir!\n\n### References\n\n* [How to configure OIDC in Argo CD](https://argo-cd.readthedocs.io/en/latest/operator-manual/user-management/#existing-oidc-provider)\n* [OIDC spec section discussing the audience claim](https://openid.net/specs/openid-connect-core-1_0.html#IDToken)\n* [JWT spec section discussing the audience claim](https://www.rfc-editor.org/rfc/rfc7519#section-4.1.3)\n\n### For more information\n\n* Open an issue in [the Argo CD issue tracker](https://github.com/argoproj/argo-cd/issues) or [discussions](https://github.com/argoproj/argo-cd/discussions)\n* Join us on [Slack](https://argoproj.github.io/community/join-slack) in channel #argo-cd\n",
  "id": "GHSA-q9hr-j4rf-8fjc",
  "modified": "2023-02-07T21:21:41Z",
  "published": "2023-01-25T22:02:52Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/argoproj/argo-cd/security/advisories/GHSA-q9hr-j4rf-8fjc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-22482"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/argoproj/argo-cd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "JWT audience claim is not verified"
}


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