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Folder escape via versioning symlinks #4286

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calmh opened this issue Aug 7, 2017 · 2 comments
Closed

Folder escape via versioning symlinks #4286

calmh opened this issue Aug 7, 2017 · 2 comments
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bug A problem with current functionality, as opposed to missing functionality (enhancement) frozen-due-to-age Issues closed and untouched for a long time, together with being locked for discussion

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@calmh
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calmh commented Aug 7, 2017 •
edited

Syncthing erronously versions symlinks when they are deleted. If a directory is then created with the same name, a file created in that directory, and the file deleted, it is moved into the symlink target.
@calmh calmh added the bug A problem with current functionality, as opposed to missing functionality (enhancement) label Aug 7, 2017
@calmh calmh added this to the Planned milestone Aug 7, 2017
calmh added a commit that referenced this issue Aug 8, 2017
@calmh
lib/model, lib/versioner: Prevent symlink attack via versioning (fixes …
a0f771c 
…#4286)

Prior to this, the following is possible:

- Create a symlink "foo -> /somewhere", it gets synced
- Delete "foo", it gets versioned
- Create "foo/bar", it gets synced
- Delete "foo/bar", it gets versioned in "/somewhere/bar"

With this change, versioners should never version symlinks.
@calmh calmh closed this as completed in f1f21bf Aug 8, 2017
@calmh calmh changed the title Placeholder issue Folder escape via versioning symlinks Aug 8, 2017
calmh added a commit that referenced this issue Aug 8, 2017
@calmh
lib/model, lib/versioner: Prevent symlink attack via versioning (fixes …
1f09488 
…#4286)

Prior to this, the following is possible:

- Create a symlink "foo -> /somewhere", it gets synced
- Delete "foo", it gets versioned
- Create "foo/bar", it gets synced
- Delete "foo/bar", it gets versioned in "/somewhere/bar"

With this change, versioners should never version symlinks.
@thekoma thekoma mentioned this issue Aug 8, 2017
Closed
calmh added a commit that referenced this issue Aug 8, 2017
@calmh
Merge branch 'master' into release
8b2df44 
* master:
  lib/versioner: Clean the versions dir of symlinks, not the full folder
  lib/model: Disable symlink attack test on Windows
  lib/model, lib/versioner: Prevent symlink attack via versioning (fixes #4286)
  gui: Add title attributes for shared devices/folders
@lfam lfam mentioned this issue Aug 16, 2017
Closed
viable-hartman pushed a commit to viable-hartman/syncthing that referenced this issue Aug 25, 2017
@calmh @viable-hartman
lib/model, lib/versioner: Prevent symlink attack via versioning (fixes …
6f44119 
…syncthing#4286)

Prior to this, the following is possible:

- Create a symlink "foo -> /somewhere", it gets synced
- Delete "foo", it gets versioned
- Create "foo/bar", it gets synced
- Delete "foo/bar", it gets versioned in "/somewhere/bar"

With this change, versioners should never version symlinks.
@abergmann
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CVE-2017-1000420 was assigned to this issue.
https://nvd.nist.gov/vuln/detail/CVE-2017-1000420

@calmh
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calmh commented Jan 3, 2018

Yep, thanks.

@st-review st-review added the frozen-due-to-age Issues closed and untouched for a long time, together with being locked for discussion label Aug 8, 2018
@syncthing syncthing locked and limited conversation to collaborators Aug 8, 2018
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