Описание
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.
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
Пакеты
github.com/argoproj/argo-cd
>= 1.8.2, < 2.3.14
2.3.14
github.com/argoproj/argo-cd
>= 2.4.0, < 2.4.20
2.4.20
github.com/argoproj/argo-cd
>= 2.5.0, < 2.5.8
2.5.8
github.com/argoproj/argo-cd
>= 2.6.0-rc1, < 2.6.0-rc5
2.6.0-rc5
Связанные уязвимости
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. T...
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
Уязвимость реализации прикладного программного интерфейса декларативного инструмента непрерывной доставки GitOps для Kubernetes Argo CD, связанная с ошибками авторизации, позволяющая нарушителю обойти установленный контроль доступа