Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. A critical vulnerability has been discovered in Argo CD starting with version 1.4.0 and prior to versions 2.1.15, 2.2.9, and 2.3.4 which would allow unauthenticated users to impersonate as any Argo CD user or role, including the admin user, by sending a specifically crafted JSON Web Token (JWT) along with the request. In order for this vulnerability to be exploited, anonymous access to the Argo CD instance must have been enabled. In a default Argo CD installation, anonymous access is disabled. The vulnerability can be exploited to impersonate as any user or role, including the built-in admin account regardless of whether it is enabled or disabled. Also, the attacker does not need an account on the Argo CD instance in order to exploit this. If anonymous access to the instance is enabled, an attacker can escalate their privileges, effectively allowing them to gain the same privileges on the cluster as the Argo CD instance, which is cluster admin in a default installation. This will allow the attacker to create, manipulate and delete any resource on the cluster. They may also exfiltrate data by deploying malicious workloads with elevated privileges, thus bypassing any redaction of sensitive data otherwise enforced by the Argo CD API. A patch for this vulnerability has been released in Argo CD versions 2.3.4, 2.2.9, and 2.1.15. As a workaround, one may disable anonymous access, but upgrading to a patched version is preferable.
Impact
Argo CD Cluster secrets might be managed declaratively using Argo CD / kubectl apply. As a result, the full secret body is stored inkubectl.kubernetes.io/last-applied-configuration annotation.
https://github.com/argoproj/argo-cd/pull/7139 introduced the ability to manage cluster labels and annotations. Since clusters are stored as secrets it also exposes the kubectl.kubernetes.io/last-applied-configuration annotation which includes full secret body. In order to view the cluster annotations via the Argo CD API, the user must have clusters, get RBAC access.
Note: In many cases, cluster secrets do not contain any actually-secret information. But sometimes, as in bearer-token auth, the contents might be very sensitive.
Patches
The bug has been patched in the following versions:
2.8.3 2.7.14 2.6.15
Workarounds
Update/Deploy cluster secret with server-side-apply flag which does not use or rely on kubectl.kubernetes.io/last-applied-configuration annotation. Note: annotation for existing secrets will require manual removal.
For more information
Open an issue in the Argo CD issue tracker or discussions Join us on Slack in channel #argo-cd
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. All unpatched versions of Argo CD starting with 1.0.0 are vulnerable to an improper access control bug, allowing a malicious user to potentially escalate their privileges to admin-level. Versions starting with 0.8.0 and 0.5.0 contain limited versions of this issue. To perform exploits, an authorized Argo CD user must have push access to an Application's source git or Helm repository or sync and override access to an Application. Once a user has that access, different exploitation levels are possible depending on their other RBAC privileges. A patch for this vulnerability has been released in Argo CD versions 2.3.2, 2.2.8, and 2.1.14. Some mitigation measures are available but do not serve as a substitute for upgrading. To avoid privilege escalation, limit who has push access to Application source repositories or sync + override access to Applications; and limit which repositories are available in projects where users have update access to Applications. To avoid unauthorized resource inspection/tampering, limit who has delete, get, or action access to Applications.
All unpatched versions of Argo CD starting with v1.0.0 are vulnerable to an improper access control bug, allowing a malicious user to potentially escalate their privileges to admin-level.
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Argo CD starting with version 1.3.0 but before versions 2.1.11, 2.2.6, and 2.3.0 is vulnerable to a path traversal bug, compounded by an improper access control bug, allowing a malicious user with read-only repository access to leak sensitive files from Argo CD's repo-server. A malicious Argo CD user who has been granted get access for a repository containing a Helm chart can craft an API request to the /api/v1/repositories/{repourl}/appdetails endpoint to leak the contents of out-of-bounds files from the repo-server. The malicious payload would reference an out-of-bounds file, and the contents of that file would be returned as part of the response. Contents from a non-YAML file may be returned as part of an error message. The attacker would have to know or guess the location of the target file. Sensitive files which could be leaked include files from other Applications' source repositories or any secrets which have been mounted as files on the repo-server. This vulnerability is patched in Argo CD versions 2.1.11, 2.2.6, and 2.3.0. The patches prevent path traversal and limit access to users who either A) have been granted Application create privileges or B) have been granted Application get privileges and are requesting details for a repourl that has already been used for the given Application. There are currently no known workarounds.
Impact
All unpatched versions of Argo CD starting with v1.5.0 are vulnerable to a path traversal vulnerability allowing a malicious user with read/write access to leak sensitive files from Argo CD's repo-server.
A malicious Argo CD user who has been granted create or update access to Applications can leak the contents of any text file on the repo-server. By crafting a malicious Helm chart and using it in an Application, the attacker can retrieve the sensitive file's contents either as part of the generated manifests or in an error message. The attacker would have to know or guess the location of the target file.
Sensitive files which could be leaked include files from other Application's source repositories (potentially decrypted files, if you are using a decryption plugin) or any secrets which have been mounted as files on the repo-server.
Patches
A patch for this vulnerability has been released in the following Argo CD versions:
v2.3.0 v2.2.6 v2.1.11
Workarounds
The only certain way to avoid the vulnerability is to upgrade.
To mitigate the problem, you can avoid storing secrets in git avoid mounting secrets as files on the repo-server avoid decrypting secrets into files on the repo-server carefully limit who can create or update Applications
References
Security documentation for the repo-server component Argo CD RBAC configuration documentation
For more information
Open an issue in the Argo CD issue tracker or discussions Join us on Slack in channel #argo-cd
Impact
All versions of Argo CD starting with v0.7.0 are vulnerable to an uncontrolled memory consumption bug, allowing an authorized malicious user to crash the repo-server service. The repo-server is a critical component of Argo CD, so crashing the repo-server effectively denies core Argo CD services (such as syncing Application updates).
To achieve denial of service, the attacker must be an authenticated Argo CD user authorized to deploy Applications from a repository which contains (or can be made to contain) a large file.
Patches
A patch for this vulnerability has been released in the following Argo CD versions:
v2.4.1 v2.3.5 v2.2.10 v2.1.16
The patch introduces a new reposerver.max.combined.directory.manifests.size config parameter, which you should tune before upgrading in production. It caps the maximum total file size of .yaml/.yml/.json files in directory-type (raw manifest) Applications. The default max is 10M per Application. This max is designed to keep any single app from consuming more than 3G of memory in the repo-server (manifests consume more space in memory than on disk). The 300x ratio assumes a maliciously-crafted manifest file. If you only want to protect against accidental excessive memory use, it is probably safe to use a smaller ratio.
If your organization uses directory-type Applications with very many manifests or very large manifests then check the size of those manifests and tune the config parameter before deploying this change to production. When testing, make sure to do a "hard refresh" in either the CLI or UI to test your directory-type App. That will make sure you're using the new max logic instead of relying on cached manifest responses from Redis.
Workarounds
There is no workaround besides upgrading.
To mitigate the issue, carefully limit 1) who can configure repos (determined by RBAC), 2) which repos are allowed (determined by Project limitations), and 3) who has push access to those repos (determined by your SCM provider configuration).
Credits
Disclosed by ADA Logics in a 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 discussions Join us on Slack in channel #argo-cd
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Argo CD starting with version 0.7.0 and prior to versions 2.1.15m 2.2.9, and 2.3.4 is vulnerable to a symlink following bug allowing a malicious user with repository write access to leak sensitive files from Argo CD's repo-server. A malicious Argo CD user with write access for a repository which is (or may be) used in a directory-type Application may commit a symlink which points to an out-of-bounds file. Sensitive files which could be leaked include manifest files from other Applications' source repositories (potentially decrypted files, if you are using a decryption plugin) or any JSON-formatted secrets which have been mounted as files on the repo-server. A patch for this vulnerability has been released in Argo CD versions 2.3.4, 2.2.9, and 2.1.15. Users of versions 2.3.0 or above who do not have any Jsonnet/directory-type Applications may disable the Jsonnet/directory config management tool as a workaround.
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. A vulnerability was found in Argo CD prior to versions 2.3.4, 2.2.9, and 2.1.15 that allows an attacker to spoof error messages on the login screen when single sign on (SSO) is enabled. In order to exploit this vulnerability, an attacker would have to trick the victim to visit a specially crafted URL which contains the message to be displayed. As far as the research of the Argo CD team concluded, it is not possible to specify any active content (e.g. Javascript) or other HTML fragments (e.g. clickable links) in the spoofed message. A patch for this vulnerability has been released in Argo CD versions 2.3.4, 2.2.9, and 2.1.15. There are currently no known workarounds.