チェックリスト

Check-Image-01: Is user/group ownership of config files set to root/glance?

Configuration files contain critical parameters and information required for smooth functioning of the component. If an unprivileged user, either intentionally or accidentally, modifies or deletes any of the parameters or the file itself then it would cause severe availability issues resulting in a denial of service to the other end users. Therefore, user ownership of such critical configuration files must be set to root and group ownership must be set to glance. Additionally, the containing directory should have the same ownership to ensure that new files are owned correctly.

以下のコマンドを実行します。

$ stat -L -c "%U %G" /etc/glance/glance-api-paste.ini | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-api.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-cache.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-manage.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-registry-paste.ini | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-registry.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-scrubber.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/glance-swift-store.conf | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/policy.json | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/schema-image.json | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance/schema.json | egrep "root glance"
$ stat -L -c "%U %G" /etc/glance | egrep "root glance"

Pass: If user and group ownership of all these configuration files is set to root and glance respectively. The above commands show output of root glance.

Fail: If the above commands do not return any output.

Check-Image-02: Are strict permissions set for configuration files?

Similar to the previous check, we recommend you set strict access permissions for such configuration files.

以下のコマンドを実行します。

$ stat -L -c "%a" /etc/glance/glance-api-paste.ini
$ stat -L -c "%a" /etc/glance/glance-api.conf
$ stat -L -c "%a" /etc/glance/glance-cache.conf
$ stat -L -c "%a" /etc/glance/glance-manage.conf
$ stat -L -c "%a" /etc/glance/glance-registry-paste.ini
$ stat -L -c "%a" /etc/glance/glance-registry.conf
$ stat -L -c "%a" /etc/glance/glance-scrubber.conf
$ stat -L -c "%a" /etc/glance/glance-swift-store.conf
$ stat -L -c "%a" /etc/glance/policy.json
$ stat -L -c "%a" /etc/glance/schema-image.json
$ stat -L -c "%a" /etc/glance/schema.json
$ stat -L -c "%a" /etc/glance

A broader restriction is also possible: if the containing directory is set to 750, the guarantee is made that newly created files inside this directory would have the desired permissions.

Pass: If permissions are set to 640 or stricter, or the containing directory is set to 750. The permissions of 640/750 translates into owner r/w, group r, and no rights to others. For example, u=rw,g=r,o=.

注釈

With Check-Image-01: Is user/group ownership of config files set to root/glance?, and permissions set to 640, root has read/write access and glance has read access to these configuration files. The access rights can also be validated using the following command. This command will only be available on your system if it supports ACLs.

$ getfacl --tabular -a /etc/glance/glance-api.conf
getfacl: Removing leading '/' from absolute path names
# file: /etc/glance/glance-api.conf
USER   root  rw-
GROUP  glance  r--
mask         r--
other        ---

失敗: パーミッションが 640 より緩くなっている場合。

Check-Image-03: Is keystone used for authentication?

注釈

This item only applies to OpenStack releases Rocky and before as auth_strategy was deprecated in Stein.

OpenStack supports various authentication strategies including noauth, and keystone. If the noauth strategy is used, then users can interact with OpenStack services without any authentication. This could be a potential risk since an attacker might gain unauthorized access to the OpenStack components. We strongly recommend that all services must be authenticated with keystone using their service accounts.

Pass: If value of parameter auth_strategy under [DEFAULT] section in /etc/glance/glance-api.conf is set to keystone and value of parameter auth_strategy under [DEFAULT] section in /etc/glance /glance-registry.conf is set to keystone.

Fail: If value of parameter auth_strategy under [DEFAULT] section in /etc/glance/glance-api.conf is set to noauth or value of parameter auth_strategy under [DEFAULT] section in /etc/glance/glance- registry.conf is set to noauth.

Check-Image-04: Is TLS enabled for authentication?

OpenStack components communicate with each other using various protocols and the communication might involve sensitive or confidential data. An attacker may try to eavesdrop on the channel in order to get access to sensitive information. All components must communicate with each other using a secured communication protocol.

Pass: If value of parameter www_authenticate_uri under [keystone_authtoken] section in /etc/glance/glance-api.conf is set to the Identity API endpoint starting with https://, and the value of the parameter insecure is under the same [keystone_authtoken] section in the same /etc/glance/glance-registry.conf is set to False.

Fail: If value of parameter www_authenticate_uri under [keystone_authtoken] section in /etc/glance/glance-api.conf is not set to Identity API endpoint starting with https://, or value of parameter insecure under the same [keystone_authtoken] section in the same /etc/glance/glance-api.conf is set to True.

Check-Image-05: Are masked port scans prevented?

The copy_from feature in Image Service API v1 supplied by Glance can allow an attacker to perform masked network port scans. If the v1 API is enabled, this policy should be set to a restricted value.

Pass: If value of parameter copy_from in /etc/glance/policy.json is set to a restricted value, for example role:admin.

Fail: If value of parameter copy_from in /etc/glance/policy.json is not set.