Security - The view and edit id is visible in the address bar - security

Question

CakePHP Version 3.5.5
The id is visible in the address bar for view and edit which for my application creates a security risk. Any logged in user at the same company can change the id in the address bar and view or edit the details
of users they are not allowed to.
IE: https://localhost/crm/users/edit/1378 can be manually changed in the address bar to https://localhost/crm/users/edit/1215 and entered. This would display the details of user 1215 which is not allowed.
To overcome this I am selecting the ids which the user is allowed to edit and checking that the id from the url is one of these ids with the following code:
public function view($id = null)
{
if ($this->request->is('get')) {
// Select the permitted ids.
if (superuser) { // example to explain only
$query = $this->Users->find()
->where(['companyid' => $cid])
->andWhere(['status' => 1])
->toArray();
}
elseif (manager) { // example to explain only
$query = $this->Users->find()
->where(['areaid' => $areaid])
->andWhere(['status' => 1])
->toArray();
}
elseif (team leader) { // example to explain only
$query = $this->Users->find()
->where(['teamid' => $teamid])
->andWhere(['status' => 1])
->toArray();
}
// Check if the edit id is in the array of permitted ids.
$ids = array_column($query, 'id');
$foundKey = array_search($id, $ids);
// If the edit id is not in the array of permitted ids redirect to blank.
if (empty($foundKey)) {
// Handle error.
}
$user = $this->Users->get($id);
$this->set('user', $user);
$this->set('_serialize', ['user']);
}
else {
// Handle error.
}
}
My question: Is the above code the best cake way of achieving this or is there a better way to do it?
This code does work but because it's to do with security I'd appreciate any input which would improve it or point out it's weakness/es.
/////////////////////////////////////////////////////////////////////////////
As requested by cgTag please see below.
My app has superusers, managers, team leaders and users.
Managers manage one area which can contain many teams.
Team Leaders lead one team and must belong to an area.
Users are assigned to an area or a team.
For example:
Area is UK
Team is England
Team is Scotland
Team is Wales
Area is USA
Team is Florida
Team is California
Team is Texas
On index - superusers see all the superusers, managers, team leaders and users in the company.
On index - managers see themself and users in their area, team leaders in their area and users in the teams.
On index - team leaders see themself and users in their team
My problem is say the manager of area UK clicks edit on one of the records and that record is displayed with a url of https://localhost/crm/users/edit/1378
Then say this disgruntled manager makes a guess and changes the url to https://localhost/crm/users/edit/1215 and submits it then this record is displayed. (This record could be anyone, a superuser, another manager, a team leader who is not in their area or a user not in their area.
This manager could then change say the email address and submit this and it's this type of situation that I need to protect against.
My fix is to reiterate the find for the superuser, manager and team leader I've done on index in the view and edit class. This ensures that say a manager can only view or edit someone in their area.
Hopefully I've explained it well enough but if not just let me know and I'll have another go.
Thanks. Z.
/////////////////////////////////////////////////////////////////////////////
Thanks cgTag, I feel a lot more confident with this approach but I cannot use this code because you have correctly assumed that I am using an id to select all the companies results but I'm using a 40 char string. I do this so I can make my sql queries more robust.
It's impossible for you to help me unless you have all the info required so I have posted an accurate representation below:
public function view($id = null)
{
if(!$this->request->is('get') || !$id) {
//throw new ForbiddenException();
echo 'in request is NOT get or id NOT set ' . '<hr />';
}
$user_id = $this->Auth->user('id');
// regular users can never view other users.
if($user_id !== $id) {
//throw new ForbiddenException();
echo 'in $user_id !== $id ' . '<hr />';
}
// Declare client id 1.
if ($this->cid1() === false) {
echo 'in throw exception ' . '<hr />';
}
else {
$c1 = null;
$c1 = $this->cid1();
}
$company_ids = $this->getCompanyIds($c1);
$area_ids = $this->getAreaIds($user_id, $c1);
$team_ids = $this->getTeamIds($user_id, $c1);
// company_id does not exist which will cause an unknown column error.
// The column I select by is cid_1 so I have changed this column to cid_1 as shown below.
$user = $this->Users->find()
->where([
'id' => $id,
'cid_1 IN' => $company_ids,
'area_id IN' => $area_ids,
'team_id IN' => $team_ids,
'status' => 1
])
->firstOrFail();
$this->set(compact('user'));
}
The functions:
public function cid1()
{
$session = $this->request->session();
if ($session->check('Cid.one')) {
$c1 = null;
$c1 = $session->read('Cid.one');
if (!is_string($c1) || is_numeric($c1) || (strlen($c1) !== 40)) {
return false;
}
return $c1;
}
return false;
}
public function getCompanyIds($c1 = null)
{
$query = $this->Users->find()
->where(['status' => 1])
->andWhere(['cid_1' => $c1]);
return $query;
}
public function getAreaIds($c1 = null, $user_id = null)
{
$query = $this->Users->find()
->where(['status' => 1])
->andWhere(['cid_1' => $c1])
->andWhere(['area_id' => $user_id]);
return $query;
}
public function getTeamIds($c1 = null, $user_id = null)
{
$query = $this->Users->find()
->where(['status' => 1])
->andWhere(['cid_1' => $c1])
->andWhere(['team_id' => $user_id]);
return $query;
}
With this code I get the following error:
Error: SQLSTATE[21000]: Cardinality violation: 1241 Operand should contain 1 column(s)
I don't know if your example will work with this new information but at least you have all the information now.
If it can be ammended great but if not I really don't mind. And I do appreciate the time you've put aside to try to help.
Thanks Z
/////////////////////////////////////////////////////////////////////////////
#tarikul05 - Thanks for the input.
Your suggestion is very similar to my first effort at addressing this security issue but I went for security through obscurity and hid the id in a 80 char string, example below.
// In a cell
public function display($id = null)
{
// Encrypt the id to pass with view and edit links.
$idArray = str_split($id);
foreach($idArray as $arrkey => $arrVal) {
$id0 = "$idArray[0]";
$id1 = "$idArray[1]";
$id2 = "$idArray[2]";
$id3 = "$idArray[3]";
}
// Generate string for the id to be obscured in.
$enc1 = null;
$enc1 = sha1(uniqid(mt_rand(), true));
$enc2 = null;
$enc2 = sha1(uniqid(mt_rand(), true));
$encIdStr = $enc1 . $enc2;
// Split the string.
$encIdArray = null;
$encIdArray = str_split($encIdStr);
// Generate the coded sequence.
$codedSequence = null;
$codedSequence = array(9 => "$id0", 23 => "$id1", 54 => "$id2", 76 => "$id3");
// Replace the id in the random string.
$idTemp = null;
$idTemp = array_replace($encIdArray, $codedSequence);
// Implode the array.
$encryptedId = null;
$encryptedId = implode("",$idTemp);
// Send the encrypted id to the view.
$this->set('encryptedId', $encryptedId);
}
And then decrypted with
// In function in the app controller
public function decryptTheId($encryptedId = null)
{
$idArray = str_split($encryptedId);
foreach($idArray as $arrkey => $arrVal) {
$id0 = "$idArray[9]";
$id1 = "$idArray[23]";
$id2 = "$idArray[54]";
$id3 = "$idArray[76]";
}
$id = null;
$id = $id0.$id1.$id2.$id3;
return $id;
}
The problem with this was that when testing I managed to get the script to error which revealed the array positions which would of undermined the security by obscurity principle and made it a lot easier for a hacker.
Your suggestion is neater than my obscurity method but I believe md5 has been cracked therefore it should not be used.
I'm no security expert but in my opinion checking the view and edit id against an array of permitted ids is the most secure way to address this.
Maybe I'm wrong but if I do it this way there's is no way a hacker no matter what they try in the address bar can see or edit data they are not meant to and it keeps the url cleaner.
What I was originally looking/hoping for was a Cake method/function which addressed this but I couldn't find anything in the cookbook.
Thanks anyway. Z.

Answer 1

I would simplify your code so that the SQL that fetches the user record only finds that record if the current user has permissions. When you're dependent upon associated data for those conditions. Follow this approach even if you have to use joins.
You create the SQL conditions and then call firstOrFail() on the query. This throws a NotFoundException if there is no match for the record.
public function view($id = null) {
if(!$this->request->is('get') || !$id) {
throw new ForbiddenException();
}
$user_id = $this->Auth->user('id');
// regular users can never view other users.
if($user_id !== $id) {
throw new ForbiddenException();
}
$company_ids = $this->getCompanyIds($user_id);
$area_ids = $this->getAreaIds($user_id);
$team_ids = $this->getTeamIds($user_id);
$user = $this->Users->find()
->where([
'id' => $id
'company_id IN' => $company_ids,
'area_id IN' => $area_ids,
'team_id IN' => $team_ids,
'status' => 1
])
->firstOrFail();
$this->set(compact('user'));
}
The above logic should be sound when a user belongsTo a hierarchical structure of data. Where by, they can view many users but only if those users belong to one of the upper associations they have access too.
It works because of the IN clause of the where conditions.
Note: The IN operator throws an error if the array is empty. When you have users who can see all "teams" just exclude that where condition instead of using an empty array.
The key here is to have functions which return an array of allowed parent associations such as; getCompanyIds($user_id) would return just the company IDs the current user is allowed access too.
I think if you implement it this way then the logic is easy to understand, the security is solid and a simple firstOrFail() prevents access.