{"id":"GHSA-q9hr-j4rf-8fjc","summary":"JWT audience claim is not verified","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'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.\n\nIf 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.\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's 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","aliases":["CVE-2023-22482","GO-2023-1520"],"modified":"2024-08-20T20:58:57.941999Z","published":"2023-01-25T22:02:52Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2023-01-25T22:02:52Z","nvd_published_at":"2023-01-26T21:18:00Z","cwe_ids":["CWE-863"],"severity":"CRITICAL"},"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"}],"affected":[{"package":{"name":"github.com/argoproj/argo-cd","ecosystem":"Go","purl":"pkg:golang/github.com/argoproj/argo-cd"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.8.2"},{"fixed":"2.3.14"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-q9hr-j4rf-8fjc/GHSA-q9hr-j4rf-8fjc.json"}},{"package":{"name":"github.com/argoproj/argo-cd","ecosystem":"Go","purl":"pkg:golang/github.com/argoproj/argo-cd"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.4.0"},{"fixed":"2.4.20"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-q9hr-j4rf-8fjc/GHSA-q9hr-j4rf-8fjc.json"}},{"package":{"name":"github.com/argoproj/argo-cd","ecosystem":"Go","purl":"pkg:golang/github.com/argoproj/argo-cd"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.5.0"},{"fixed":"2.5.8"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-q9hr-j4rf-8fjc/GHSA-q9hr-j4rf-8fjc.json"}},{"package":{"name":"github.com/argoproj/argo-cd","ecosystem":"Go","purl":"pkg:golang/github.com/argoproj/argo-cd"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.6.0-rc1"},{"fixed":"2.6.0-rc5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-q9hr-j4rf-8fjc/GHSA-q9hr-j4rf-8fjc.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}