Snapd

The snapctl component within snapd allows a confined snap to interact with the snapd daemon to take certain privileged actions on behalf of the snap. It was found that snapctl did not properly parse command-line arguments, allowing an unprivileged user to trigger an authorised action on behalf of the snap that would normally require administrator privileges to perform. This could possibly allow an unprivileged user to perform a denial of service or similar.

Published: 2024-05-31T21:02:19.979Z
Updated: 2024-09-06T19:48:49.508Z

In snapd versions prior to 2.62, snapd failed to properly check the destination of symbolic links when extracting a snap. The snap format is a squashfs file-system image and so can contain symbolic links and other file types. Various file entries within the snap squashfs image (such as icons and desktop files etc) are directly read by snapd when it is extracted. An attacker who could convince a user to install a malicious snap which contained symbolic links at these paths could then cause snapd to write out the contents of the symbolic link destination into a world-readable directory. This in-turn could allow an unprivileged user to gain access to privileged information.

Published: 2024-07-25T19:39:41.050Z
Updated: 2024-08-02T01:03:51.700Z

In snapd versions prior to 2.62, snapd failed to properly check the file type when extracting a snap. The snap format is a squashfs file-system image and so can contain files that are non-regular files (such as pipes or sockets etc). Various file entries within the snap squashfs image (such as icons etc) are directly read by snapd when it is extracted. An attacker who could convince a user to install a malicious snap which contained non-regular files at these paths could then cause snapd to block indefinitely trying to read from such files and cause a denial of service.

Published: 2024-07-25T19:28:05.480Z
Updated: 2024-08-02T01:03:51.709Z

In snapd versions prior to 2.62, when using AppArmor for enforcement of sandbox permissions, snapd failed to restrict writes to the $HOME/bin path. In Ubuntu, when this path exists, it is automatically added to the users PATH. An attacker who could convince a user to install a malicious snap which used the 'home' plug could use this vulnerability to install arbitrary scripts into the users PATH which may then be run by the user outside of the expected snap sandbox and hence allow them to escape confinement.

Published: 2024-07-25T19:05:23.299Z
Updated: 2024-08-01T18:48:21.887Z

Using the TIOCLINUX ioctl request, a malicious snap could inject contents into the input of the controlling terminal which could allow it to cause arbitrary commands to be executed outside of the snap sandbox after the snap exits. Graphical terminal emulators like xterm, gnome-terminal and others are not affected - this can only be exploited when snaps are run on a virtual console.

Published: 2023-09-01T18:41:47.820Z
Updated: 2024-10-01T13:08:45.851Z