Follow up for anyone coming here because of Ubuntu's unique (pre-19.10) behavior of not changing $HOME when calling sudo; if this is causing you problems, you should change your calling of sudo to include the -H param which will force sudo on Ubuntu to change HOME to the target user's homedir, instead of leaving it as the calling user's homedir.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to sudo in Ubuntu. https://bugs.launchpad.net/bugs/1556302 Title: Ubuntu patch to add HOME to env_keep makes custom commands vulnerable by default Status in Release Notes for Ubuntu: New Status in sudo package in Ubuntu: Fix Released Status in sudo source package in Xenial: In Progress Status in sudo source package in Bionic: In Progress Status in sudo source package in Cosmic: In Progress Status in sudo source package in Disco: In Progress Status in sudo source package in Eoan: Fix Released Bug description: [impact] sudo does not set HOME to the target user's HOME [test case] ddstreet@thorin:~$ sudo printenv | grep HOME HOME=/home/ddstreet [regression potential] this is a significant behavior change. As mentioned in comment 11 (and later, and other bugs duped to this, and the mailing list discussion, etc) users of Ubuntu so far have been used to running sudo with their own HOME set, not root's HOME. Therefore, it's inappropriate to change this behavior for existing releases; this should be changed starting in Eoan, and only the sudo and sudoers man pages changed in previous releases to indicate the actual behavior of sudo in those releases. [other info] Shortly after upstream changed the behavior, the patch to keep HOME as the calling (instead of target) user was added in bug 760140. For quick reference to anyone coming to this bug, the pre-19.10 behavior (of sudo keeping the calling user's $HOME) can be disabled by running 'sudo visudo' and adding this line: Defaults always_set_home or, run sudo with the -H param. -- original description: -- I wanted to allow certain users to execute a python script as another user, so I created the following sudoers config: Defaults env_reset source_user ALL=(target_user) NOPASSWD: /home/target_user/bin/script.py This results in a highly insecure Python environment because the source user can set HOME and override any Python package by putting files in $HOME/.local/lib/python*/site-packages/. This should be a safe configuration because the default behaviour (as specified in the man page) is that env_reset will replace HOME with the target user's home directory. The "env_reset" option even has special behaviour for bash which has its own potential environment vulnerabilities. However there is an Ubuntu-specific patch in the package (keep_home_by_default.patch) that makes sudo preserve HOME by default, which negates the correct behaviour of "env_reset". It should not be necessary to explicitly specify the "always_set_home" option in order to negate this patch. The patch should be removed and the default /etc/sudoers should explicitly add HOME to "env_keep" for the "allow admins to run any command as root" entries, to get the desired behaviour without creating security issues for other sudoers commands. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-release-notes/+bug/1556302/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp