Security
Headlines
HeadlinesLatestCVEs

Headline

GHSA-q9hr-j4rf-8fjc: JWT audience claim is not verified

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.

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:

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

ghsa
Open in Source
#vulnerability#git#auth

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.

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:

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

  • How to configure OIDC in Argo CD
  • OIDC spec section discussing the audience claim
  • JWT spec section discussing the audience claim

For more information

  • Open an issue in the Argo CD issue tracker or discussions
  • Join us on Slack in channel #argo-cd

References

  • GHSA-q9hr-j4rf-8fjc

Related news

CVE-2023-22482: JWT audience claim is not verified

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Versions of Argo CD starting with v1.8.2 and prior to 2.3.13, 2.4.19, 2.5.6, and 2.6.0-rc-3 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 ...

Red Hat Security Advisory 2023-0468-01

Red Hat Security Advisory 2023-0468-01 - Red Hat Openshift GitOps is a declarative way to implement continuous deployment for cloud native applications.

Red Hat Security Advisory 2023-0466-01

Red Hat Security Advisory 2023-0466-01 - Red Hat Openshift GitOps is a declarative way to implement continuous deployment for cloud native applications.

Red Hat Security Advisory 2023-0467-01

Red Hat Security Advisory 2023-0467-01 - Red Hat Openshift GitOps is a declarative way to implement continuous deployment for cloud native applications. Issues addressed include a bypass vulnerability.

RHSA-2023:0468: Red Hat Security Advisory: Red Hat OpenShift GitOps security update

An update is now available for Red Hat OpenShift GitOps 1.5.9 Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-22482: ArgoCD: JWT audience claim is not verified

RHSA-2023:0467: Red Hat Security Advisory: Red Hat OpenShift GitOps security update

An update is now available for Red Hat OpenShift GitOps 1.7. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-22482: ArgoCD: JWT audience claim is not verified * CVE-2023-22736: argocd: Controller reconciles apps outside configured namespaces when sharding is enabled

ghsa: Latest News

GHSA-jh6x-7xfg-9cq2: Searching Opencast may cause a denial of service
ghsa