| name | cloud-docker-registry |
| description | Find and loot exposed container registries — image pull/push, secrets baked in layers, and registry misconfig. Load on exposed Docker registry (port 5000, /v2/), a registry URL, harbor/ECR/ GCR/ACR references, or "container registry". Signals: /v2/_catalog, registry:2, unauth pull/push.
|
| domain | cloud |
| type | technique |
| stability | learning |
| modes | ["bugbounty","pentest"] |
| severity | high |
| owasp | ["A05:2021-Security-Misconfiguration"] |
| cwe | ["CWE-522","CWE-306"] |
| mitre | ["T1525","T1552.001"] |
| tools | ["docker","crane","curl","trufflehog"] |
| schema_version | 1 |
Exposed container registry
When it applies
A Docker/OCI registry is reachable — a self-hosted registry (:5000, /v2/), or a cloud one
(ECR/GCR/ACR/Harbor) with weak auth. Images are goldmines: source, configs, and baked-in secrets.
Why it works
Registries are often deployed without auth ("internal only") or with over-broad pull access. Image
layers preserve everything added at build time — .env files, cloud keys, private source,
tokens — even if a later layer deletes them, earlier layers keep them.
Method
- Detect & enumerate:
curl -s https://registry:5000/v2/_catalog (repo list) and
.../v2/<repo>/tags/list. registry:2 banner / an unauth /v2/ = exposed.
- Pull images:
docker pull registry:5000/<repo>:<tag> or crane pull (no docker daemon).
Anonymous pull of private images is the finding.
- Mine layers for secrets:
crane export/docker save then scan with trufflehog filesystem
/ grep for keys, .env, kubeconfig, cloud creds (→ validate with code-review-secrets-detection).
- Push (critical): if anonymous/weak push works, you can poison images (supply-chain) — prove
with a harmless tag, don't tamper real images.
- Cloud registries: test misconfigured ECR/GCR/ACR policies; leaked registry creds → pull private images.
Gotchas
- Scan all layers/history, not just the final image — secrets hide in intermediate layers.
- Anonymous push is critical (supply-chain); anonymous pull of private images is high — rate accordingly.
- Only pull what proves the issue; images can be large and contain real data — handle carefully.
Verify success
Anonymous/unauthorized pull of a private image, a live secret extracted from its layers, or a
successful (harmless) push proving write access.
References
Docker registry API docs; crane/trufflehog; "hacking Docker registries" write-ups.
