nextcloud / nextcloud/guests

Versions of files get leaked to guests

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#372 0 comments 0 reactions 0 assignees View on GitHub

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bug integration
Dominant language
JavaScript
Stars
61
Forks
34
Avg merge
3d 19h
Merged PRs (30d)
22

Description

Hi guys,

we just noticed a security vulnerability in the guests app. If the app files_versions is not on the app whitelist for guests, they still see the versions tab in the file details and can download all versions of a file.

This was already mentioned in #338, but I think it should be more labeled as a vulnerability / data leakage than information being shown in the sidepanel.

I assume this is comes from how urls are whitelisted and assigned to apps. As far as I see the versions get downloaded using DAV, which is always being whitelisted in the code.

I hope this can be fixed soon, because the app is really nice and useful, but we cannot have guests download old versions of our files.

Thanks!

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reading the guest app whitelist handling and the DAV path used for file-version downloads, then compare the related issue #338. Verify both the versions tab and version downloads when files_versions is not whitelisted; done means guests can access neither.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
authorization, security
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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