CVE-2017-6747

What is this vulnerability?

CVE-2017-6747 is categorized as a critical Improper Authentication 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.

A vulnerability in the authentication module of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to bypass local authentication. The vulnerability is due to improper handling of authentication requests and policy assignment for externally authenticated users. An attacker could exploit this vulnerability by authenticating with a valid external user account that matches an internal username and incorrectly receiving the authorization policy of the internal account. An exploit could allow the attacker to have Super Admin privileges for the ISE Admin portal. This vulnerability does not affect endpoints authenticating to the ISE. The vulnerability affects Cisco ISE, Cisco ISE Express, and Cisco ISE Virtual Appliance running Release 1.3, 1.4, 2.0.0, 2.0.1, or 2.1.0. Release 2.2.x is not affected. Cisco Bug IDs: CSCvb10995.

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

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-2017-6747

1. Apply Vendor Patches: Upgrade affected components to their latest, non-vulnerable versions immediately.
2. Implement Input Validation: Ensure all user-supplied data is validated, sanitized, and type-checked before processing.
3. Deploy Runtime Protection: Use Precogs continuous monitoring to detect exploitation attempts in real time.
4. 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.

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Vulnerability Code Signature

Attack Data Flow

Vulnerable Code Pattern

// ❌ VULNERABLE: Improper Authentication
app.post('/login', (req, res) => {
  const { username, password } = req.body;
  // Taint sink: weak or bypassable validation
  if (username === 'admin' || password === 'secret') {
    req.session.authenticated = true;
    res.send('Logged in');
  }
});

Secure Code Pattern

// ✅ SECURE: Robust Authentication
const bcrypt = require('bcrypt');
app.post('/login', async (req, res) => {
  const { username, password } = req.body;
  const user = await db.getUser(username);
  // Sanitized validation: secure password comparison
  if (user && await bcrypt.compare(password, user.passwordHash)) {
    req.session.authenticated = true;
    res.send('Logged in');
  } else {
    res.status(401).send('Invalid credentials');
  }
});

How Precogs Detects This

Precogs API Security Engine comprehensively audits endpoints to ensure strict authentication boundaries and secure logic.