[Learn what's the difference between _natural paths_ and _hash paths_](https://docs.silverstripe.org/en/4/developer_guides/files/file_migration/#natural-path-vs-hash-path)
on the Silverstripe CMS documentation.
Alternatively, you can try accessing the file directly in a incognito/private
browser session. To do so, navigate to a restricted file in the asset
administration interface inside the CMS. On the right-hand panel,
right-click on the file preview and copy the link to the file. If you paste the
link into a private/incognito browser session and can access the file, then your
file can be viewed by the general public.
## Running the migration tasks
The 4.4.6/4.5.2 Silverstripe CMS releases add new file migration subtasks to
retroactively protect files that have been wrongly exposed. They are 3 new
subtasks.
*`migrate-folders` creates versioning metadata for Silverstripe CMS 3 Folder
records.
*`normalise-access` protect files that have been wrongly exposed.
*`relocate-userform-uploads-2020-9280` move files uploaded through the
userforms module to their intended folder.
### Do I need to run the migration tasks?
Based on the nature of your Silverstripe CMS project, you may need to run all of
the tasks, some of the them, or none of them.
You do not need to run any of the subtasks if the following three conditions are
all true:
* your project was not migrated from Silverstripe CMS 3
* your project does not include the userforms module, or if it does, no userform
has been configured to allow file uploads
* your project does not programmatically create files or allow users to upload
files via a custom form(s).
If your project was upgraded from a Silverstripe CMS 3 project, you should
minimally run the `migrate-folders` subtask.
If your project programmatically creates files or allows users to upload files
via a user form or a custom form, you should run the `normalise-access` task.
If your project allows users to upload files via a user form and was upgraded from
a Silverstripe CMS 3 project, you may need to run all 3 tasks.
If your project was migrated from Silverstripe CMS 3 and allows users to upload
files via custom forms, you should run the `migrate-folders` subtask. However,
you also will need to manually protect the affected files. The easiest way
could be to find all the folders affected through a SQL query before you run the
task. Then you may be able to find all the custom forms using those folder IDs
accordingly. Unfortunately, we cannot provide any automation for this scenario.
You should also consider making your `/Uploads` folder protected manually
(via CMS) as a best practice, since it is publicly accessible by default.
### What do the migration tasks do?
Take some time to read the following descriptions and understand how running
each subtask will affect your Silverstripe CMS project. `migrate-folders` and
`normalise-access` are relatively quick and have no side affects.
`relocate-userform-uploads-2020-9280` is the most complex of the three subtasks
and has the most potential side effects. You should take special care to
understand what it does before running it.
#### migrate-folders subtask
The `migrate-folders` subtask validates that every "Folder" record in the
`File` table has a matching entry in the `File_Live` table. This will prevent
future file uploads from being accidentally stored in the publicly accessible
"Uploads" folder.
It does not retroactively move files that have been stored in the wrong Folder
to their intended destination.
To find out what Folders on your Silverstripe CMS project will be affected by
running the `migrate-folders` subtask, you can run the following SQL query:
```sql
-- This query is targeted to MySQL. You may need to adapt it for other SQL databases.
SELECT
File.ID,
File.Name
FROM
File
LEFT JOIN
File_Live
ON File_Live.ID = File.ID
WHERE
File_Live.ID IS NULL
AND File.ClassName = 'SilverStripe\\Assets\\Folder'
```
Note that the file migration task will now run this step by default, so you
won't need to explicitly run the `migrate-folders` task for future
Silverstripe CMS 3 upgrades.
[Learn how to migrate files from Silverstripe CMS 3 to Silverstripe CMS 4](https://docs.silverstripe.org/en/4/developer_guides/files/file_migration/#migration-from-silverstripe-3-to-silverstripe-4-4-or-later)
on the Silverstripe CMS documentation.
#### normalise-access subtask
The `normalise-access` subtask goes through each individual File record in a
Silverstripe CMS project and confirms that the `canView` result for anonymous
users matches the physical location of the file. If the physical file is
publicly visible while it's `canView` method returns `false` for anonymous
users, it will be moved to the protected location.
#### relocate-userform-uploads-2020-9280 task
Because of the `CVE-2020-9280` vulnerability, you may have Folders without a
matching entries in their "Live" table. User form file upload submissions
may end up being stored in an incorrect publicly-accessible location under the
following conditions:
* you have user forms that accept file uploads
* the file upload field is configured to save the file in a folder that was
created in Silverstripe CMS 3
* the targeted folder has not been manually saved since your Silverstripe CMS 4
upgrade.
If those 3 conditions are met, you should consider running the
`relocate-userform-uploads-2020-9280` subtask.
`relocate-userform-uploads-2020-9280` will go through each user form file upload
submission and verify that the uploaded file is stored in the folder specified
in the matching file upload user form field. If the file is stored in the wrong
folder, the task will move the file to the Folder specified in the user form
upload field configuration at the time the file was uploaded.
##### What if I have a custom upload form?
If you have a written a controller operating in the "Live" stage that creates
files or receives uploaded files, and that controller is configured to save
files in a folder created in Siverstripe CMS 3, your files may have been stored
in the wrong location. Unfortunately, we can not provide a migration task for
each custom scenario.
The `relocate-userform-uploads-2020-9280` only works because there's a record of
where the file was meant to be uploaded on the user form page.
If you have a small number of files, it might be practical to manually update
their location via the asset administration interface in the CMS. Otherwise, you
may have to write your own migration task to achieve the same purpose.
### How do I run the migration tasks?
`migrate-folders`, `normalise-access` and `relocate-userform-uploads-2020-9280`
have been written as subtasks of the regular file migration task. The file
migration task can be run in 3 different ways:
* in the browser under `dev/tasks`
* on the command line
* as a queued job.
You can run each subtask individually or you can run all three subtasks in one
go. The `only` parameter controls which subtasks will be run. You can get
multiple subtask to run by specifying them as a comma-separated list:
`only=migrate-folders,normalise-access,relocate-userform-uploads-2020-9280`. The subtasks
are executed in a pre-defined sequence, so the order they appeared in the
comma-separated list is irrelevant.
Which ever way you choose to run the sub tasks, you **MUST run `migrate-folders`
before `relocate-userform-uploads-2020-9280`**. The recommended order to run the subtasks
is:
1.`migrate-folders`
2.`normalise-access`
3.`relocate-userform-uploads-2020-9280`.
[Learn more about the File Migration Task on the Silverstripe CMS documentation](https://docs.silverstripe.org/en/4/developer_guides/files/file_migration/)
#### Testing the file migration task first
If possible, you should consider running the task in a development or testing
environment first, either on a snapshot of your production environment or on a
subset of your live data. Make sure you have back ups configured on your
production environment and a recovery strategy in place in case things go badly.
#### Running the task in the browser
Running the file migration task in the browser should only be considered if you
have a small number of files. It is susceptible to timeout if the task runs for
too long. Depending on your application settings, you may not have the output
logs of the tasks run. Please consider the other options first.
To run the task in the browser, navigate to `/dev/tasks/MigrateFileTask` and
provide the `only` parameter as a GET parameter on your request. e.g.:
* 2020-03-08 [b269d8749](https://github.com/silverstripe/silverstripe-framework/commit/b269d874909cd70bb60c1a2974ea5446b43b0436) Register new sub tasks to fix files affected by CVE-2020-9280 and CVE-2019-12245 (Serge Latyntcev)
* 2020-03-04 [12ea7cd](https://github.com/silverstripe/silverstripe-assets/commit/12ea7cd2037bebcb3196dd5e3aaa72e6dbc7c7b2) Create NormaliseAccessMigrationHelper to fix files affected by CVE-2019-12245 (Maxime Rainville)
