CVE-2019-9756
Authorization Bypass Through User-Controlled Key in An issue was discovered in GitLab Community and Enterprise Edition 10
Executive Summary
CVE-2019-9756 is a critical severity vulnerability affecting api-security. It is classified as CWE-639. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"Precogs API Security Engine performs deep analysis of API endpoints using Code Property Graph traversal, detecting broken authentication, mass assignment, BOLA/IDOR, and SSRF vulnerabilities across REST, GraphQL, and gRPC interfaces before they reach production."
What is this vulnerability?
CVE-2019-9756 is categorized as a critical Authorization Bypass Through User-Controlled Key flaw with a CVSS base score of 9.8. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
An issue was discovered in GitLab Community and Enterprise Edition 10.x (starting from 10.8) and 11.x before 11.6.10, 11.7.x before 11.7.6, and 11.8.x before 11.8.1. It has Incorrect Access Control, a different vulnerability than CVE-2019-9732.
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 9.8 (CRITICAL) |
| Vector String | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Published | April 17, 2019 |
| Last Modified | November 21, 2024 |
| Related CWEs | CWE-639 |
Impact on Systems
✅ Unauthorized Data Access: Attackers can bypass authorization controls to access other users' data or administrative endpoints.
✅ Account Takeover: Broken authentication or authorization may enable full account compromise without valid credentials.
✅ API Abuse: Exploiting this vulnerability enables mass data harvesting or destructive operations through unprotected API endpoints.
How to Fix and Mitigate CVE-2019-9756
- Apply Vendor Patches: Upgrade affected components to their latest, non-vulnerable versions immediately.
- Implement Input Validation: Ensure all user-supplied data is validated, sanitized, and type-checked before processing.
- Deploy Runtime Protection: Use Precogs continuous monitoring to detect exploitation attempts in real time.
- Audit Dependencies: Review and update all third-party libraries and transitive dependencies.
Defending with Precogs AI
Precogs API Security Engine performs deep analysis of API endpoints using Code Property Graph traversal, detecting broken authentication, mass assignment, BOLA/IDOR, and SSRF vulnerabilities across REST, GraphQL, and gRPC interfaces before they reach production.
Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | API Endpoint (REST/GraphQL) |
| Vector | Missing or flawed authorization checks on the requested resource |
| Sink | Direct interaction with database or internal microservice |
| Impact | Unauthorized data access, BOLA/IDOR, Account Takeover |
Vulnerable Code Pattern
// ❌ VULNERABLE: Missing Authorization (BOLA)
app.get('/api/users/:id/data', async (req, res) => {
const userId = req.params.id;
// Taint sink: fetches data for requested ID without verifying ownership
const data = await db.getUserData(userId);
res.json(data);
});
Secure Code Pattern
// ✅ SECURE: Strict Resource Authorization
app.get('/api/users/:id/data', requireAuth, async (req, res) => {
const requestedId = req.params.id;
const authenticatedId = req.user.id;
// Sanitized validation: check ownership
if (requestedId !== authenticatedId && !req.user.isAdmin) {
return res.status(403).json({ error: "Unauthorized access" });
}
const data = await db.getUserData(requestedId);
res.json(data);
});
How Precogs Detects This
Precogs API Security Engine comprehensively audits all exposed endpoints to guarantee strict session validation and resource authorization.