CVE-2017-1000189
ejs vulnerable to DoS due to weak input validation
Executive Summary
CVE-2017-1000189 is a critical severity vulnerability affecting appsec. It is classified as an undisclosed flaw. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"Architecturally, this flaw occurs due to within Nodejs ejs version older, allowing the improper handling of untrusted input. In a real-world scenario, an attacker could exploit this by intercept or modify sensitive data flows before they reach secure enclaves. By intercepting insecure data flows from user input directly to rendering sinks, Precogs is designed to harden the environment against lateral movement."
What is this vulnerability?
CVE-2017-1000189 is categorized as a critical Application Verification Flaw flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
nodejs ejs version older than 2.5.5 is vulnerable to a denial-of-service due to weak input validation in ejs.renderFile().
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 | N/A |
| Published | March 5, 2018 |
| Last Modified | November 8, 2023 |
| Related CWEs | N/A |
Impact on Systems
✅ Unauthorized Access: Flaws in application logic can permit unauthorized interaction with protected APIs.
✅ Data Manipulation: Adversaries may alter critical application states, such as user roles or configurations.
✅ Service Disruption: Improper error handling or unvalidated inputs can lead to resource exhaustion.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Defense in Depth Implement multi-layered validation (client-side, API gateway, and server-side).
2. Least Privilege Ensure backend service accounts operate with the absolute minimum rights required.
3. Security Regression Testing Integrate automated semantic security scanning into the deployment pipeline.
Vulnerability Signature
// Generic Application Security Flaw (Node.js)
app.post('/api/update-profile', (req, res) =\> \{
// DANGEROUS: Mass Assignment / Object Injection
// Attacker can pass \{ "isAdmin": true, "email": "..." \}
User.update(\{ id: req.user.id \}, req.body);
// SECURED: Explicitly select permitted fields
const \{ email, displayName, bio \} = req.body;
User.update(\{ id: req.user.id \}, \{ email, displayName, bio \});
\});
References and Sources
- NVD — CVE-2017-1000189
- MITRE — CVE-2017-1000189
- Application Security Vulnerabilities
- OSV.dev Database
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Untrusted User Input |
| Vector | Input flows through the application logic without sanitization |
| Sink | Execution or Rendering Sink |
| Impact | Application compromise, Logic Bypass, Data Exfiltration |
Vulnerable Code Pattern
# ❌ VULNERABLE: Unsanitized Input Flow
def process_request(request):
user_input = request.GET.get('data')
# Taint sink: processing untrusted data
execute_logic(user_input)
return {"status": "success"}
Secure Code Pattern
# ✅ SECURE: Input Validation & Sanitization
def process_request(request):
user_input = request.GET.get('data')
# Sanitized boundary check
if not is_valid_format(user_input):
raise ValueError("Invalid input format")
sanitized_data = sanitize(user_input)
execute_logic(sanitized_data)
return {"status": "success"}
How Precogs Detects This
Precogs AI Analysis Engine maps untrusted input directly to execution sinks to catch complex application security vulnerabilities.\n