CVE-2021-4119 (PHP, published 2021-12-15T20:15Z)
Description: value: bookstack is vulnerable to Improper Access Control
Severity: HIGH (CVSS v3 base score: 9.8)
Weakness: NVD-CWE-Other \u2014 Other
NVD is only using a subset of CWE for mapping instead of the entire CWE, and the weakness type is not covered by that subset.
Repository: https://github.com/bookstackapp/bookstack
Files changed:
app/Auth/UserRepo.php
app/Http/Controllers/UserSearchController.php
resources/views/users/delete.blade.php
tests/User/UserManagementTest.php
tests/User/UserSearchTest.php
Commit message: Addressed user detail harvesting issue

Altered access & usage of the /search/users/select endpoint with the
following changes:
- Removed searching of email address to prevent email detail discovery
  via hunting via search queries.
- Required the user to be logged in and have permission to manage users
  or manage permissions on items in some way.
- Removed the user migration option on user delete unless they have
  permission to manage users.

For #3108
Reported in https://huntr.dev/bounties/135f2d7d-ab0b-4351-99b9-889efac46fca/
Reported by @haxatron


Vulnerable code:
            ->withLastActivityAt()
use Illuminate\Database\Eloquent\Builder;
        $query = User::query()->orderBy('name', 'desc')
            $query->where(function (Builder $query) use ($search) {
                $query->where('email', 'like', '%' . $search . '%')
                    ->orWhere('name', 'like', '%' . $search . '%');
            });
        $users = $query->get();

        return view('form.user-select-list', compact('users'));
            <hr class="my-l">

            <div class="grid half gap-xl v-center">
                <div>
                    <label class="setting-list-label">{{ trans('settings.users_migrate_ownership') }}</label>
                    <p class="small">{{ trans('settings.users_migrate_ownership_desc') }}</p>
                <div>
                    @include('form.user-select', ['name' => 'new_owner_id', 'user' => null, 'compact' => false])
                </div>
            </div>

Fixed code:
     * Note: Due to the use of email search this should only be used when
     * user is assumed to be trusted. (Admin users).
     * Email search can be abused to extract email addresses.
            ->scopes(['withLastActivityAt'])
        $hasPermission = signedInUser() && (
                   userCan('users-manage')
                || userCan('restrictions-manage-own')
                || userCan('restrictions-manage-all')
        );

        if (!$hasPermission) {
            $this->showPermissionError();
        }

        $query = User::query()
            ->orderBy('name', 'asc')
            $query->where('name', 'like', '%' . $search . '%');
        return view('form.user-select-list', [
            'users' => $query->get(),
        ]);
            @if(userCan('users-manage'))
                <hr class="my-l">

                <div class="grid half gap-xl v-center">
                    <div>
                        <label class="setting-list-label">{{ trans('settings.users_migrate_ownership') }}</label>
                        <p class="small">{{ trans('settings.users_migrate_ownership_desc') }}</p>
                    </div>
                    <div>
                        @include('form.user-select', ['name' => 'new_owner_id', 'user' => null, 'compact' => false])
                    </div>
            @endif
    public function test_migrate_option_hidden_if_user_cannot_manage_users()
    {
        $editor = $this->getEditor();

        $resp = $this->asEditor()->get("settings/users/{$editor->id}/delete");
        $resp->assertDontSee('Migrate Ownership');
        $resp->assertDontSee('new_owner_id');

        $this->giveUserPermissions($editor, ['users-manage']);

        $resp = $this->asEditor()->get("settings/users/{$editor->id}/delete");
        $resp->assertSee('Migrate Ownership');
        $resp->assertSee('new_owner_id');
    }

<?php

namespace Tests\User;

use BookStack\Auth\User;
use Tests\TestCase;

class UserSearchTest extends TestCase
{

    public function test_select_search_matches_by_name()
    {
        $viewer = $this->getViewer();
        $admin = $this->getAdmin();
        $resp = $this->actingAs($admin)->get('/search/users/select?search=' . urlencode($viewer->name));

        $resp->assertOk();
        $resp->assertSee($viewer->name);
        $resp->assertDontSee($admin->name);
    }

    public function test_select_search_shows_first_by_name_without_search()
    {
        /** @var User $firstUser */
        $firstUser = User::query()->orderBy('name', 'desc')->first();
        $resp = $this->asAdmin()->get('/search/users/select');

        $resp->assertOk();
        $resp->assertSee($firstUser->name);
    }

    public function test_select_search_does_not_match_by_email()
    {
        $viewer = $this->getViewer();
        $editor = $this->getEditor();
        $resp = $this->actingAs($editor)->get('/search/users/select?search=' . urlencode($viewer->email));

        $resp->assertDontSee($viewer->name);
    }

    public function test_select_requires_right_permission()
    {
        $permissions = ['users-manage', 'restrictions-manage-own', 'restrictions-manage-all'];
        $user = $this->getViewer();

        foreach ($permissions as $permission) {
            $resp = $this->actingAs($user)->get('/search/users/select?search=a');
            $this->assertPermissionError($resp);

            $this->giveUserPermissions($user, [$permission]);
            $resp = $this->actingAs($user)->get('/search/users/select?search=a');
            $resp->assertOk();
            $user->roles()->delete();
            $user->clearPermissionCache();
        }
    }

    public function test_select_requires_logged_in_user()
    {
        $this->setSettings(['app-public' => true]);
        $defaultUser = User::getDefault();
        $this->giveUserPermissions($defaultUser, ['users-manage']);

        $resp = $this->get('/search/users/select?search=a');
        $this->assertPermissionError($resp);
    }

}