UNIX Symbolic Link (Symlink) Following

Summary

Apptainer is an open source container platform. In Apptainer versions prior to 1.4.5, a container can disable two of the forms of the little "used --security" option, in particular the forms "--security=apparmor:<profile>" and "--security=selinux:<label> "which otherwise put restrictions on operations that containers can do. The "--security" option has always been mentioned in Apptainer documentation as being a feature for the root user, although these forms do also work for unprivileged users on systems where the corresponding feature is enabled. Apparmor is enabled by default on Debian-based distributions and SElinux is enabled by default on RHEL-based distributions, but on SUSE it depends on the distribution version. This vulnerability is fixed in 1.4.5.