USN-6940-2: snapd vulnerabilities

USN-6940-1 fixed vulnerabilities in snapd. This update provides the corresponding updates for Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. Original advisory details: Neil McPhail discovered that snapd did not properly restrict writes to the /home/jslarraz/bin path in the AppArmor profile for snaps using the home plug. An attacker who could convince a user to install a malicious snap could use this vulnerability to escape the snap sandbox. (CVE-2024-1724) Zeyad Gouda discovered that snapd failed to properly check the file type when extracting a snap. An attacker who could convince a user to install a malicious snap containing non-regular files could then cause snapd to block indefinitely while trying to read from such files and cause a denial of service. (CVE-2024-29068) Zeyad Gouda discovered that snapd failed to properly check the destination of symbolic links when extracting a snap. An attacker who could convince a user to install a malicious snap containing crafted symbolic links could then cause snapd to write out the contents of the symbolic link destination into a world-readable directory. This in-turn could allow a local unprivileged user to gain access to privileged information. (CVE-2024-29069)