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A Cross-Site Scripting (XSS) vulnerability in external service creation allows an authenticated attacker to inject HTML/script payloads into external service names, which may execute in a user’s browser when rendered by administrative web interfaces.
Prior to v2.4.0, external service registration endpoints did not strictly enforce alphanumeric character restrictions on service names. An operator or attacker with API access could register a service using a crafted name containing HTML elements (such as <iframe src="...">). If an administrative web UI rendered the unescaped service name, arbitrary script execution could occur in the context of the user’s browser session. The vulnerability stems from insufficient input sanitization on the service name parameter during external service registration. When a service is registered via the `POST /services` endpoint, the provided name is stored and later rendered in administrative interfaces without proper escaping. This allows an attacker to craft a malicious service name containing JavaScript, which executes when an administrator views the service list or details page. The attack requires authentication, limiting the attacker pool to operators or users with API access privileges. The vulnerability is classified as Self-XSS / Stored XSS, as the payload is persistently stored and can affect any user who views the compromised service entry.
DailyCVE Form:
Platform: eKuiper
Version: <2.4.0
Vulnerability: Stored XSS
Severity: Low
Date: 2026-09-01
Prediction: Already Patched (v2.4.0)
What Undercode Say:
Check current eKuiper version
ekuiper --version
Verify if vulnerable (versions below 2.4.0 are affected)
Example API request to list services (may reveal unescaped names)
curl -X GET http://localhost:9081/api/v1/services
Test payload injection via service creation
curl -X POST http://localhost:9081/api/v1/services \
-H "Content-Type: application/json" \
-d '{"name":"
<
iframe src=\"javascript:alert(1337)\">","type":"rest","url":"http://example.com"}'
Exploit: (Educational Purposes!)
- Craft a JSON definition for an external service with a malicious name:
{ "name": "</li> </ol> < iframe src=\"javascript:alert(1337)\">", "type": "rest", "url": "http://attacker.com/endpoint" }2. Optionally, place the JSON inside a ZIP archive with a filename containing the same XSS payload (e.g.,
<iframe src="javascript:alert1337">.json).
3. Upload the ZIP or send the JSON directly to the `POST /services` endpoint using an authenticated API request.
4. Upon successful registration, the unescaped service name is stored in the database.
5. When an administrator accesses the web UI that renders service names, the injected script executes in their browser context.Protection:
- Upgrade to eKuiper version 2.4.0 or higher, where strict alphanumeric identifier validation (
validate.ValidateID) is enforced on all external service creation and update endpoints, rejecting invalid characters. - Restrict access to eKuiper management endpoints (
POST /services) with authentication and network-level firewalls to limit the attacker pool. - Implement input validation and output encoding on all administrative web interfaces that render user-supplied data.
- Monitor logs for unusual service names containing HTML tags or JavaScript patterns.
Impact:
Self-XSS / Stored XSS leading to potential session token leakage or unauthorized actions in the context of the affected user’s browser session. An attacker could hijack an administrative session, perform actions on behalf of the administrator, or exfiltrate sensitive information displayed in the UI.
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💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by ThousandsSources:
Reported By: github.com
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- Upgrade to eKuiper version 2.4.0 or higher, where strict alphanumeric identifier validation (
