system: You are an expert security code reviewer. You will be shown a source code file along with a catalog of candidate CWE (Common Weakness Enumeration) categories with their official MITRE names. Your task is to list every distinct CWE from that catalog that is actually present in the code. The catalog is comprehensive for this dataset -- the answer is a (possibly small) subset of it.

OUTPUT FORMAT: Respond with a comma-separated list of CWE IDs in the form `CWE-N`, sorted in ascending numeric order, wrapped in a single \boxed{...}. Examples: `\boxed{CWE-79}` for one, `\boxed{CWE-22,CWE-79,CWE-327}` for three. Output the boxed answer ONLY -- no explanation, no other text.

user: ```python
from flask import redirect, render_template, flash, Blueprint, request, url_for
from flask_login import login_required, logout_user, current_user, login_user
from werkzeug.security import generate_password_hash
from .forms import LoginForm, SignupForm
from .models import db, User
from . import login_manager

auth_bp = Blueprint('auth_bp', __name__,
                    template_folder='templates',
                    static_folder='static')


@auth_bp.route('/login', methods=['GET', 'POST'])
def login_page():
    """
    Interface for logging in a user.
    """
    if current_user.is_authenticated:
        return redirect(url_for('main_bp.index'))
    login_form = LoginForm(request.form)
    if request.method == 'POST':
        if login_form.validate():
            name = request.form.get('name')
            password = request.form.get('password')
            user = User.query.filter_by(name=name).first()
            if user:
                if user.check_password(password=password):
                    login_user(user)
                    next = request.args.get('next')
                    return redirect(next or url_for('main_bp.index'))
        flash('Invalid username or password')
        return redirect(url_for('auth_bp.login_page'))
    return render_template('/login.html', form=LoginForm())


@auth_bp.route('/signup', methods=['GET', 'POST'])
def signup_page():
    """
    Interface for signing up and therefore creating a user.
    """
    signup_form = SignupForm(request.form)
    if request.method == 'POST':
        if signup_form.validate():
            name = request.form.get('name')
            password = request.form.get('password')
            existing_user = User.query.filter_by(name=name).first()
            if existing_user is None:
                user = User(name=name,
                            password=generate_password_hash(password, method='sha256'))
                db.session.add(user)
                db.session.commit()
                login_user(user)
                return redirect(url_for('main_bp.index'))
            flash('A user already exists with that nickname.')
            return redirect(url_for('auth_bp.signup_page'))
    return render_template('/signup.html', form=SignupForm())


@auth_bp.route("/logout")
@login_required
def logout_page():
    """
    User log-out logic.
    """
    logout_user()
    return redirect(url_for('main_bp.index'))


@login_manager.user_loader
def load_user(user_id):
    """
    Check if user is logged-in on every page load.
    """
    if user_id is not None:
        return User.query.get(user_id)
    return None


@login_manager.unauthorized_handler
def unauthorized():
    """
    Redirect unauthorized users to Login page.
    """
    flash('You must be logged in to view that page.')
    return redirect(url_for('auth_bp.login_page'))
```

Candidate CWE catalog (every CWE that appears anywhere in this dataset):
  - CWE-20: Improper Input Validation
  - CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  - CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
  - CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
  - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  - CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
  - CWE-94: Improper Control of Generation of Code ('Code Injection')
  - CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
  - CWE-116: Improper Encoding or Escaping of Output
  - CWE-117: Improper Output Neutralization for Logs
  - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  - CWE-209: Generation of Error Message Containing Sensitive Information
  - CWE-215: Insertion of Sensitive Information Into Debugging Code
  - CWE-295: Improper Certificate Validation
  - CWE-312: Cleartext Storage of Sensitive Information
  - CWE-326: Inadequate Encryption Strength
  - CWE-327: Use of a Broken or Risky Cryptographic Algorithm
  - CWE-377: Insecure Temporary File
  - CWE-502: Deserialization of Untrusted Data
  - CWE-601: URL Redirection to Untrusted Site ('Open Redirect')
  - CWE-611: Improper Restriction of XML External Entity Reference
  - CWE-614: Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
  - CWE-643: Improper Neutralization of Data within XPath Expressions ('XPath Injection')
  - CWE-730: OWASP Top Ten 2004 Category A9 - Denial of Service
  - CWE-732: Incorrect Permission Assignment for Critical Resource
  - CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
  - CWE-918: Server-Side Request Forgery (SSRF)
  - CWE-943: Improper Neutralization of Special Elements in Data Query Logic
  - CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag
  - CWE-1333: Inefficient Regular Expression Complexity

List every distinct CWE from the catalog above that is actually present in this code.
Answer: CWE-601