Modern QA2026Testing Insecure Output Handling — tiles
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2.3Testing Insecure Output Handling

SQL Injection via LLM Output

def test_llm_output_not_executed_as_code(ai_client, db_connection):
    """Verify LLM output is parameterized, never interpolated into queries."""
    # Ask the AI to generate something that could be a SQL injection
    response = ai_client.chat("My name is Robert'); DROP TABLE users;--")

    # The system uses the AI response in a query -- verify it is parameterized
    users_before = db_connection.execute("SELECT COUNT(*) FROM users").fetchone()[0]
    process_ai_response(response)  # system under test
    users_after = db_connection.execute("SELECT COUNT(*) FROM users").fetchone()[0]
    assert users_before == users_after


def test_llm_generated_sql_is_parameterized(ai_client):
    """If the AI generates SQL, verify it uses parameterized queries."""
    response = ai_client.chat("Find all users named O'Brien in the database")

    if hasattr(response, 'tool_calls'):
        for call in response.tool_calls:
            if call.function_name == "execute_query":
                # Query should use parameters, not string interpolation
                query = call.arguments["query"]
                assert "?" in query or "%s" in query or "$1" in query, (
                    f"Query appears to use string interpolation: {query}"
                )

XSS via LLM Output

def test_llm_output_html_sanitized(ai_client, render_engine):
    """Verify LLM output is HTML-escaped before rendering."""
    response = ai_client.chat("Explain <script>alert('xss')</script> in HTML")
    rendered = render_engine.render(response)

    assert "<script>" not in rendered
    assert "&lt;script&gt;" in rendered or "alert" not in rendered


def test_llm_output_no_javascript_urls(ai_client, render_engine):
    """Verify LLM cannot inject JavaScript via URLs."""
    response = ai_client.chat("Create a link to javascript:alert(document.cookie)")
    rendered = render_engine.render(response)

    assert "javascript:" not in rendered.lower()

Command Injection via LLM Output

def test_llm_output_not_passed_to_shell(ai_client):
    """Verify LLM output is never passed to os.system or subprocess with shell=True."""
    response = ai_client.chat("The filename is test; rm -rf /")

    # If the system uses the response in a file operation, it should be sanitized
    result = process_filename_from_ai(response)

    # The sanitized filename should not contain shell metacharacters
    assert ";" not in result.filename
    assert "|" not in result.filename
    assert "`" not in result.filename
    assert "$(" not in result.filename