It was found that rpm did not properly handle RPM installations when a destination path was a symbolic link to a directory, possibly changing ownership and permissions of an arbitrary directory, and RPM files being placed in an arbitrary destination. An attacker, with write access to a directory in which a subdirectory will be installed, could redirect that directory to an arbitrary location and gain root privilege.
https://github.com/rpm-software-management/rpm/commit/f2d3be2a8741234faaa96f5fd05fdfdc75779a79
https://github.com/rpm-software-management/rpm/commit/c815822c8bdb138066ff58c624ae83e3a12ebfa9