By creating a specially crafted webdav request that contains an external entity it is possible to read files from a liferay server. and echo these back in the response. You could use this for instance to download configuration files containing database passwords or ssh keys located in a users home folder
Proof of concept:
Code demonstrating the vulnerability can be found at
https://github.com/jelmerk/LPS-24562-proof
http://www.exploit-db.com/sploits/18763.tar.gz