Apptainer vulnerabilities

Apptainer before version 1.5.1 has a vulnerability in Image.AuthorizedPath that applies plain string-prefix matching to the limit container paths directive in apptainer.conf, so an allowed path such as /data/safe also authorizes a sibling path such as /data/safe-but-unsafe. A local user can consequently run a container from a directory outside the administrator's intended allowlist when Apptainer operates in setuid mode.

Apptainer versions less than 1.4.5 allow a container to disable two forms of the little-used --security option, specifically --security=apparmor:<profile> and --security=selinux:<label>, which otherwise restrict container operations. The --security option is documented as a root feature, but these forms also work for unprivileged users on systems where the corresponding feature is enabled. The vulnerability is fixed in 1.4.5.

Apptainer is an open source container platform. Version 1.2.0-rc.2 introduced an ineffective privilege drop when requesting container network setup, allowing subsequent functions to be called with root privileges.