widelands-dev team mailing list archive

[Jari Hautio <724344@xxxxxxxxxxxxxxxxxx>]

Good to have it fixed in trunk.

Could you also post a news item to inform users about the issue. Users
should be advised to only join remote games that are hosted by people
they trust. I initially marked this as security vulneralibility, so this
bug has limited visibility.

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https://bugs.launchpad.net/bugs/724344

Title:
  Security issue in sending files in network game

Status in Widelands:
  Fix Committed

Bug description:
  Network games have capability to send savegames and maps over network.
  Receiving player first checks if the file exists, and if it exists,
  existing file is renamed before new file is received. Handling of the
  received file is not secure as FileSystem classes support using ".."
  in path to go out of filesystem root. For example sending a file name
  like "../.bashrc" allows some nasty things to happen.

  To fix this issue either FileSystem code should enforce that file
  accesses stay within created file system's root. Alternatively paths
  coming from network should be validated and  "..",  "~" and "/"
  accesses should be filtered out. Perhaps it's wise to implement both.