Description
DataNodes in Apache Hadoop 2.0.0 alpha does not check the BlockTokens of clients when Kerberos is enabled and the DataNode has checked out the same BlockPool twice from a NodeName, which might allow remote clients to read arbitrary blocks, write to blocks to which they only have read access, and have other unspecified impacts.
Remediation
References
http://archives.neohapsis.com/archives/bugtraq/2012-07/0049.html
http://www.securityfocus.com/bid/54358
https://www.cloudera.com/documentation/other/security-bulletins/topics/csb_topic_1.html