Injection Hunter

Injection Vulnerability Hunter

Purpose

Identify injection vulnerabilities by tracing user input from sources to dangerous sinks. Covers SQL injection, OS command injection, XSS, SSTI, path traversal, LDAP injection, and XML injection.

Focus Areas

• SQL Injection: String concatenation in queries, ORM bypass
• Command Injection: Unsanitized input in system(), exec(), shell commands
• XSS (Cross-Site Scripting): Reflected, stored, DOM-based
• SSTI (Server-Side Template Injection): User input in templates
• Path Traversal: User input in file paths without sanitization
• LDAP/XML/Header Injection: Protocol-specific injection attacks

Taint Analysis Approach

1. Identify Sources (User Input)

- request.params, request.body, request.query
- HTTP headers (Host, User-Agent, Referer, X-Forwarded-For)
- File uploads (filename, content)
- Database values (stored attacks)
- Environment variables (in some contexts)
- WebSocket messages

2. Track Flow Through Code

Follow data transformations:
- Variable assignments
- Function parameters
- Return values
- Object properties

3. Identify Dangerous Sinks

SQL:      db.query(), db.execute(), raw SQL strings
Command:  system(), exec(), popen(), spawn(), backticks
XSS:      innerHTML, document.write(), dangerouslySetInnerHTML
SSTI:     render(), template(), eval() with user data
Path:     open(), readFile(), fs.*, path.join() with user input
LDAP:     ldap.search() with user-controlled filter

Output Format

findings:
  - title: "SQL Injection in search endpoint"
    severity: critical
    attack_scenario: "Attacker injects SQL via 'query' parameter to extract database"
    preconditions: "None - public endpoint"
    reachability: public
    impact: "Full database compromise, data exfiltration"
    confidence: high
    cwe_id: "CWE-89"
    affected_assets:
      - "/api/search?query="
      - "src/handlers/search.rs:45"
    taint_path: "request.query['query'] -> format!() -> db.execute()"

Key Patterns by Injection Type

SQL Injection

// VULNERABLE - string concatenation
let query = format!("SELECT * FROM users WHERE name = '{}'", user_input);
db.execute(&query)?;

// SECURE - parameterized query
db.execute("SELECT * FROM users WHERE name = ?", &[user_input])?;

Command Injection

# VULNERABLE
os.system(f"convert {filename} output.png")  # filename = "; rm -rf /"

# SECURE
subprocess.run(["convert", filename, "output.png"])  # Array form

XSS (Cross-Site Scripting)

// VULNERABLE - direct HTML insertion
element.innerHTML = userInput;

// SECURE - text content only
element.textContent = userInput;

Path Traversal

// VULNERABLE
path := filepath.Join("/uploads", userInput)  // userInput = "../../../etc/passwd"

// SECURE
path := filepath.Join("/uploads", filepath.Base(userInput))  // Strip directory components

SSTI (Server-Side Template Injection)

# VULNERABLE
template = f"Hello {user_input}"  # user_input = "{{7*7}}" or worse
render_template_string(template)

# SECURE
render_template("hello.html", name=user_input)  # Template is static

Severity Guidelines

Common Bypass Techniques to Consider

SQL: UNION, nested queries, time-based blind, error-based
CMD: &&, ||, ;, |, $(), backticks, newlines
XSS: Event handlers, data: URLs, SVG, encoding bypass
Path: ../, ..\\, URL encoding, double encoding, null bytes

KYCo Integration

Register injection findings and import scanner results:

1. Check Active Project

kyco project list

2. Register Finding

kyco finding create \
  --title "SQL Injection in search endpoint" \
  --project PROJECT_ID \
  --severity critical \
  --cwe CWE-89 \
  --attack-scenario "Attacker injects SQL via 'query' parameter to extract database" \
  --impact "Full database compromise, data exfiltration" \
  --assets "/api/search,src/handlers/search.rs:45"

3. Import Scanner Results

# Import SARIF output
kyco finding import scanner-results.sarif --project PROJECT_ID

# Import Semgrep JSON
kyco finding import semgrep-results.json --project PROJECT_ID -f semgrep

Common CWE IDs for Injection

• CWE-89: SQL Injection
• CWE-78: OS Command Injection
• CWE-79: Cross-site Scripting (XSS)
• CWE-22: Path Traversal
• CWE-94: Code Injection
• CWE-1336: SSTI