Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Implemented possible solution for path traversal #28

Open
wants to merge 5 commits into
base: dev-0.3
Choose a base branch
from

Conversation

chris18191
Copy link

No description provided.

@schenkd schenkd self-requested a review July 1, 2020 17:13
@schenkd schenkd self-assigned this Jul 1, 2020
Copy link
Owner

@schenkd schenkd left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hey Chris, thanks for your PR. It looks good and you're solving a problem for the v0.3 release, thanks for that!

config_file = os.path.join(nginx_path, name)

if not os.path.commonprefix(os.path.realpath(config_file), nginx_path):
return flask.make_response({'success': False}), 200
Copy link
Owner

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would choose a different status code. For example a 400 (Bad Request) or 403 (Forbidden).

Copy link

@erikgeiser erikgeiser Jul 1, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Also note that os.path.commonprefix(("/a/b", "/c/d")) returns "/" which is truthy, so the condition is not met. And commonprefix takes an iterable and not variadic arguments so I think this errors out. Maybe use something like os.path.realpath(config_file).startswith(os.path.realpath(nginx_path) + os.sep) (though not as this ugly oneliner maybe).

@@ -57,6 +62,9 @@ def get_domains():
sites_available = []
sites_enabled = []

if not os.path.exists(config_path):
errorMessage = 'The config folder "{}" does not exists.'.format(config_path)
return flask.render_template('domains.html', errorMessage=errorMessage, sites_available=(), sites_enabled=()), 200
Copy link
Owner

@schenkd schenkd Jul 1, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Classic case of Java developer. Lower CamelCase is uncommon in Python. error_message would be nice! :)

Copy link
Owner

@schenkd schenkd Jul 1, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would also like to have the string formatting with f-string syntax. Then it will be consistent in the code.

error_message = f'The config folder "{config_path}" doesn't exists.'

@@ -1,6 +1,11 @@
<div class="column">

<div class="ui cards" id="domain_cards">
{% if errorMessage %}
<div>
{{errorMessage}}
Copy link
Owner

@schenkd schenkd Jul 1, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It is functional, but you could enhance it with a message from the semantic framework. Here is a link to the component: Error Messages

@schenkd schenkd changed the base branch from master to dev-0.3 July 1, 2020 17:26
@schenkd schenkd assigned chris18191 and unassigned schenkd Jul 1, 2020
@erikgeiser
Copy link

It seems like you addressed the path traversal issue only in a single endpoint. Looking through endpoints.py, it seems that most API endpoints work rather similar an possibly share the same issue.

@chris18191
Copy link
Author

I added a new function to generate valid paths or return None if the path is not valid, e.g. it is no subdirectory of the given folder.
Errors can now also easily be visualized by calling rendeError, which makes use Semantics error message.

@schenkd
Copy link
Owner

schenkd commented Jul 2, 2020

I added a new function to generate valid paths or return None if the path is not valid, e.g. it is no subdirectory of the given folder.
Errors can now also easily be visualized by calling rendeError, which makes use Semantics error message.

@chris18191 First of all, thank you very much for your efforts. I see you're using lower camel-case everywhere. I did not want to mention every method in the review. Could you adapt it to the Python convention? Unfortunately, I will not be able to do an extensive review before the weekend.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

Possible arbitrary file access though Path Traversal vulnerability in some situations
3 participants