Authenticated users are able to update passwords without providing their
current password
---

### Summary ###
An authenticated user is able to change their password without providing their
current password. This allows compromised authentication tokens to be used to
permanently compromise a user account.

### Affected Services / Software ###
Horizon, Keystone, Identity, Grizzly

### Discussion ###
Horizon allows a user to change their own password, which uses the Identity API
to perform the password change. A user is required to supply their current
password to successfully perform a password change. This requirement prevents a
malicious user from stealing a user's authentication token and changing that
user's password to permanently compromise their account. With this additional
password check, a compromised authentication token only compromises the user
account until the token is no longer valid due to expiration or revocation.

When using the Identity v3 API, a user is able to successfully change their
password without supplying the correct current password. This leaves users
vulnerable to permanently compromised accounts if their authentication token is
compromised. The Identity v2 API is not vulnerable to this issue, as it has a
separate API call for updating user passwords that properly validates the
current password.

### Recommended Actions ###
In the OpenStack Grizzly release, a user is allowed to update the attributes in
their own entry by default. It is recommended that you restrict user updates to
only be allowed by admin users. This is done by setting the "update_user"
policy to "admin_required" in Keystone's policy.json file. Here is an example
snippet of a properly configured policy.json file:

---- begin example policy.json snippet ----
    "identity:get_user": [["rule:admin_required"]],
    "identity:list_users": [["rule:admin_required"]],
    "identity:create_user": [["rule:admin_required"]],
    "identity:update_user": [["rule:admin_required"]],
    "identity:delete_user": [["rule:admin_required"]],
---- end example policy.json snippet ----

This change has the side-effect of restricting a user from updating any of
their own attributes, not just their password.

In the OpenStack Havana release, the default policy is to only allow admin
users to update attributes in user entries. In addition, Horizon will not
allow a user to change their own password if it is using the Identity v3 API,
even if Keystone is configured to allow users to update their own entries.
Despite this restriction in Horizon, it is recommended to leave the default
"update_user" policy setting as is, as an attacker could target Keystone
directly without using Horizon to initiate a password change.

### Contacts / References ###
This OSSN : https://bugs.launchpad.net/ossn/+bug/1237989
Original LaunchPad Bug : https://bugs.launchpad.net/keystone/+bug/1237989
OpenStack Security ML : openstack-security@lists.openstack.org
OpenStack Security Group : https://launchpad.net/~openstack-ossg
CVE: CVE-2013-4471