Program: CWE-287
Project: CVE-2021-41129
Buggy source:
<?php

namespace Pterodactyl\Http\Controllers\Auth;

use Pterodactyl\Models\User;
use Illuminate\Auth\AuthManager;
use Illuminate\Http\JsonResponse;
use PragmaRX\Google2FA\Google2FA;
use Illuminate\Contracts\Config\Repository;
use Illuminate\Contracts\Encryption\Encrypter;
use Illuminate\Database\Eloquent\ModelNotFoundException;
use Pterodactyl\Http\Requests\Auth\LoginCheckpointRequest;
use Illuminate\Contracts\Cache\Repository as CacheRepository;
use Pterodactyl\Contracts\Repository\UserRepositoryInterface;
use Pterodactyl\Repositories\Eloquent\RecoveryTokenRepository;

class LoginCheckpointController extends AbstractLoginController
{
    /**
     * @var \Illuminate\Contracts\Cache\Repository
     */
    private $cache;

    /**
     * @var \Pterodactyl\Contracts\Repository\UserRepositoryInterface
     */
    private $repository;

    /**
     * @var \PragmaRX\Google2FA\Google2FA
     */
    private $google2FA;

    /**
     * @var \Illuminate\Contracts\Encryption\Encrypter
     */
    private $encrypter;

    /**
     * @var \Pterodactyl\Repositories\Eloquent\RecoveryTokenRepository
     */
    private $recoveryTokenRepository;

    /**
     * LoginCheckpointController constructor.
     */
    public function __construct(
        AuthManager $auth,
        Encrypter $encrypter,
        Google2FA $google2FA,
        Repository $config,
        CacheRepository $cache,
        RecoveryTokenRepository $recoveryTokenRepository,
        UserRepositoryInterface $repository
    ) {
        parent::__construct($auth, $config);

        $this->google2FA = $google2FA;
        $this->cache = $cache;
        $this->repository = $repository;
        $this->encrypter = $encrypter;
        $this->recoveryTokenRepository = $recoveryTokenRepository;
    }

    /**
     * Handle a login where the user is required to provide a TOTP authentication
     * token. Once a user has reached this stage it is assumed that they have already
     * provided a valid username and password.
     *
     * @return \Illuminate\Http\JsonResponse|void
     *
     * @throws \PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     * @throws \Exception
     * @throws \Illuminate\Validation\ValidationException
     */
    public function __invoke(LoginCheckpointRequest $request): JsonResponse
    {
        if ($this->hasTooManyLoginAttempts($request)) {
            $this->sendLockoutResponse($request);
        }

        $token = $request->input('confirmation_token');
        try {
            /** @var \Pterodactyl\Models\User $user */
            $user = User::query()->findOrFail($this->cache->get($token, 0));
        } catch (ModelNotFoundException $exception) {
            $this->incrementLoginAttempts($request);

            return $this->sendFailedLoginResponse(
                $request,
                null,
                'The authentication token provided has expired, please refresh the page and try again.'
            );
        }

        // Recovery tokens go through a slightly different pathway for usage.
        if (!is_null($recoveryToken = $request->input('recovery_token'))) {
            if ($this->isValidRecoveryToken($user, $recoveryToken)) {
                return $this->sendLoginResponse($user, $request);
            }
        } else {
            $decrypted = $this->encrypter->decrypt($user->totp_secret);

            if ($this->google2FA->verifyKey($decrypted, (string) $request->input('authentication_code') ?? '', config('pterodactyl.auth.2fa.window'))) {
                $this->cache->delete($token);

                return $this->sendLoginResponse($user, $request);
            }
        }

        $this->incrementLoginAttempts($request);

        return $this->sendFailedLoginResponse($request, $user, !empty($recoveryToken) ? 'The recovery token provided is not valid.' : null);
    }

    /**
     * Determines if a given recovery token is valid for the user account. If we find a matching token
     * it will be deleted from the database.
     *
     * @return bool
     *
     * @throws \Exception
     */
    protected function isValidRecoveryToken(User $user, string $value)
    {
        foreach ($user->recoveryTokens as $token) {
            if (password_verify($value, $token->token)) {
                $token->delete();

                return true;
            }
        }

        return false;
    }
}


Fixed version (ground truth):
<?php

namespace Pterodactyl\Http\Controllers\Auth;

use Carbon\CarbonInterface;
use Carbon\CarbonImmutable;
use Pterodactyl\Models\User;
use Illuminate\Http\JsonResponse;
use PragmaRX\Google2FA\Google2FA;
use Illuminate\Contracts\Encryption\Encrypter;
use Illuminate\Database\Eloquent\ModelNotFoundException;
use Pterodactyl\Http\Requests\Auth\LoginCheckpointRequest;
use Illuminate\Contracts\Validation\Factory as ValidationFactory;

class LoginCheckpointController extends AbstractLoginController
{
    private const TOKEN_EXPIRED_MESSAGE = 'The authentication token provided has expired, please refresh the page and try again.';

    private ValidationFactory $validation;

    private Google2FA $google2FA;

    private Encrypter $encrypter;

    /**
     * LoginCheckpointController constructor.
     */
    public function __construct(Encrypter $encrypter, Google2FA $google2FA, ValidationFactory $validation)
    {
        parent::__construct();

        $this->google2FA = $google2FA;
        $this->encrypter = $encrypter;
        $this->validation = $validation;
    }

    /**
     * Handle a login where the user is required to provide a TOTP authentication
     * token. Once a user has reached this stage it is assumed that they have already
     * provided a valid username and password.
     *
     * @return \Illuminate\Http\JsonResponse|void
     *
     * @throws \PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     * @throws \Exception
     * @throws \Illuminate\Validation\ValidationException
     */
    public function __invoke(LoginCheckpointRequest $request): JsonResponse
    {
        if ($this->hasTooManyLoginAttempts($request)) {
            $this->sendLockoutResponse($request);
        }

        $details = $request->session()->get('auth_confirmation_token');
        if (!$this->hasValidSessionData($details)) {
            $this->sendFailedLoginResponse($request, null, self::TOKEN_EXPIRED_MESSAGE);
        }

        if (!hash_equals($request->input('confirmation_token') ?? '', $details['token_value'])) {
            $this->sendFailedLoginResponse($request);
        }

        try {
            /** @var \Pterodactyl\Models\User $user */
            $user = User::query()->findOrFail($details['user_id']);
        } catch (ModelNotFoundException $exception) {
            $this->sendFailedLoginResponse($request, null, self::TOKEN_EXPIRED_MESSAGE);
        }

        // Recovery tokens go through a slightly different pathway for usage.
        if (!is_null($recoveryToken = $request->input('recovery_token'))) {
            if ($this->isValidRecoveryToken($user, $recoveryToken)) {
                return $this->sendLoginResponse($user, $request);
            }
        } else {
            $decrypted = $this->encrypter->decrypt($user->totp_secret);

            if ($this->google2FA->verifyKey($decrypted, (string) $request->input('authentication_code') ?? '', config('pterodactyl.auth.2fa.window'))) {
                return $this->sendLoginResponse($user, $request);
            }
        }

        $this->sendFailedLoginResponse($request, $user, !empty($recoveryToken) ? 'The recovery token provided is not valid.' : null);
    }

    /**
     * Determines if a given recovery token is valid for the user account. If we find a matching token
     * it will be deleted from the database.
     *
     * @return bool
     *
     * @throws \Exception
     */
    protected function isValidRecoveryToken(User $user, string $value)
    {
        foreach ($user->recoveryTokens as $token) {
            if (password_verify($value, $token->token)) {
                $token->delete();

                return true;
            }
        }

        return false;
    }

    /**
     * Determines if the data provided from the session is valid or not. This
     * will return false if the data is invalid, or if more time has passed than
     * was configured when the session was written.
     *
     * @param array $data
     * @return bool
     */
    protected function hasValidSessionData(array $data): bool
    {
        $validator = $this->validation->make($data, [
            'user_id' => 'required|integer|min:1',
            'token_value' => 'required|string',
            'expires_at' => 'required',
        ]);

        if ($validator->fails()) {
            return false;
        }

        if (!$data['expires_at'] instanceof CarbonInterface) {
            return false;
        }

        if ($data['expires_at']->isBefore(CarbonImmutable::now())) {
            return false;
        }

        return true;
    }
}