blob: 1af88a4ff956cc8a451cb6b23aeb8422a78a1798 [file] [log] [blame]
- module:
- introduced: 0.4.0
fixed: 2.2.11
- module:
- introduced: 2.3.0
fixed: 2.3.6
vulnerable_at: 2.3.5
- module:
- introduced: 2.4.0
fixed: 2.4.5
vulnerable_at: 2.4.4
summary: Argo CD certificate verification is skipped for connections to OIDC providers
description: |-
### Impact
All versions of Argo CD starting with v0.4.0 are vulnerable to an improper
certificate validation bug which could cause Argo CD to trust a malicious (or
otherwise untrustworthy) OIDC provider.
(Note: external OIDC provider support was added in v0.11.0. Before that version,
the notes below apply only to the bundled Dex instance.)
You are impacted if 1) have SSO enabled and 2) insecure mode is _not_ enabled on
the API server. In this case, certificate verification is skipped when
connecting to your OIDC provider for the following tasks: verifying auth tokens
on API requests and handling SSO login flows. If you are using the bundled Dex
instance but have _not_ set the `--dex-server` flag on the API server to an
HTTPS address, then certificate verification is not being skipped (because [TLS
is not enabled by default for the bundled Dex
Argo CD sends requests to the configured OIDC provider (either the bundled Dex
instance or an external provider) to 1) retrieve the [OpenID
2) to retrieve the OIDC provider's key set (at the location determined by the
[OIDC provider's configured
and 3) (during an SSO login) to exchange an authorization code for a token.
(Note: Starting with v2.3.0, certificate verification is _not_ skipped when
handling an SSO login flow if 1) you are not using the bundled Dex OIDC provider
and 2) you have set `oidc.config.rootCA` in the `argocd-cm` ConfigMap.
Certificate verification is still skipped when verifying tokens on API calls.)
Skipping certificate verification when communicating with the OIDC provider
opens Argo CD to a variety of risks. For example, if an attacker can
successfully intercept, decrypt, and respond to requests bound for the
configured OIDC provider (a machine-in-the-middle attack), they could
theoretically issue a "valid" admin token. Verifying the OIDC provider's
certificate provides an extra layer of protection against such an attack.
### Patches
A patch for this vulnerability has been released in the following Argo CD
* v2.4.5
* v2.3.6
* v2.2.11
To preserve backwards compatibility, this patch adds a
`oidc.tls.insecure.skip.verify` option to the `argocd-cm` ConfigMap. The default
is `"false"`. Before resorting to setting this, you should try to get
certificate verification to work. If you are using the bundled Dex instance,
user your Argo CD API server's [TLS
since the API server acts as a reverse proxy to Dex. If you are using an
external OIDC provider, [set the `rootCA`
If these fail, be sure you are aware of the risks before setting
`oidc.tls.insecure.skip.verify: "true"`.
### Workarounds
There is no complete workaround besides upgrading.
#### Partial mitigation when using an external OIDC provider
If you are using an external OIDC provider (not the bundled Dex instance), then
you can mitigate the issue by setting the `oidc.config.rootCA` field in the
`argocd-cm` ConfigMap. If your OIDC provider's certificate is self-signed or
otherwise invalid, you must set the rootCA to a certificate that enables
verification. If the OIDC provider's certificate passes _without_ an additional
root CA, then you can set `oidc.config.rootCA` to a bogus non-empty string such
as `"force cert verification"`. The API server will log a warning, but otherwise
things should work fine.
```yaml metadata: name: argocd-cm data: oidc.config: | ... rootCA: | force cert
verification ```
This mitigation _only_ forces certificate validation when the API server handles
login flows. It does not force certificate verification when verifying tokens on
API calls. To fully resolve the vulnerability, you must upgrade.
### References
* [Argo CD SSO configuration
### Credits
@jannfis and @crenshaw-dev discovered the vulnerability when reviewing notes
from ADA Logics' security audit of the Argo project sponsored by CNCF and
facilitated by OSTIF. Thanks to Adam Korczynski and David Korczynski for their
work on the audit.
### For more information
* Open an issue in [the Argo CD issue
tracker]( or
* Join us on [Slack]( in channel
- CVE-2022-31105
- GHSA-7943-82jg-wmw5
- web:
- advisory:
- package:
- web:
- web:
- 'lint: bad version "2.2.11": invalid version: should be v0 or v1, not v2'
- 'lint: redundant non-advisory reference to GHSA-7943-82jg-wmw5'