Red Hat Security Advisory 2014-1400-01 – Apache POI is a library providing Java API for working with OOXML document files. It was found that Apache POI would resolve entities in OOXML documents. A remote attacker able to supply OOXML documents that are parsed by Apache POI could use this flaw to read files accessible to the user running the application server, and potentially perform more advanced XML External Entity attacks. It was found that Apache POI would expand an unlimited number of entities in OOXML documents. A remote attacker able to supply OOXML documents that are parsed by Apache POI could use this flaw to trigger a denial of service attack via excessive CPU and memory consumption.