An issue in Apache HBase affects the optional "Thrift 1" API server when running over HTTP. There is a race-condition which could lead to authenticated sessions being incorrectly applied to users, e.g. one authenticated user would be considered a different user or an unauthenticated user would be treated as an authenticated user. https://issues.apache.org/jira/browse/HBASE-20664 implements a fix for this issue. It has been fixed in versions: 1.2.6.1, 1.3.2.1, 1.4.5, 2.0.1.

Apache HBase 0.92.x before 0.92.3 and 0.94.x before 0.94.9, when the Kerberos features are enabled, allows man-in-the-middle attackers to disable bidirectional authentication and obtain sensitive information via unspecified vectors.