*** This bug is a security vulnerability *** Public security bug reported:
I have included a debdiff imported from upstream for the below security advisory for ark. I have tested the patch in ppa with the sample archive issued in the advisory and can confirm it works without any noticeable issues. KDE Project Security Advisory ============================= Title: Ark: maliciously crafted TAR archive with symlinks can install files outside the extraction directory. Risk Rating: Important CVE: CVE-2020-24654 Versions: ark <= 20.08.0 Author: Elvis Angelaccio <[email protected]> Date: 27 August 2020 Overview ======== A maliciously crafted TAR archive containing symlink entries would install files anywhere in the user's home directory upon extraction. Proof of concept ================ For testing, an example of malicious archive can be found at https://github.com/jwilk/traversal-archives/releases/download/0/dirsymlink.tar Impact ====== Users can unwillingly install files like a modified .bashrc, or a malicious script placed in ~/.config/autostart. Workaround ========== Before extracting a downloaded archive using the Ark GUI, users should inspect it to make sure it doesn't contain symlink entries pointing outside the extraction folder. The 'Extract' context menu from the Dolphin file manager shouldn't be used. Solution ======== Ark 20.08.1 skips maliciously crafted symlinks when extracting TAR archives. Alternatively, https://invent.kde.org/utilities/ark/-/commit/8bf8c5ef07b0ac5e914d752681e470dea403a5bd can be applied to previous releases. Credits ======= Thanks to Fabian Vogt for reporting this issue and for fixing it. ** Affects: ark (Ubuntu) Importance: Undecided Status: New ** Patch added: "CVE-2020-24654-tar-symlinks-outside-extraction-directory.debdiff" https://bugs.launchpad.net/bugs/1893465/+attachment/5405512/+files/CVE-2020-24654-tar-symlinks-outside-extraction-directory.debdiff ** Information type changed from Private Security to Public Security ** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2020-24654 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1893465 Title: KDE Project Security Advisory: Ark: maliciously crafted TAR archive with symlinks can install files outside the extraction directory. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ark/+bug/1893465/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
