CVE 2010-0094
Unspecified vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business 6 Update 18 and 5.0 Update 23 allows remote attackers to affect confidentiality, integrity, and availability via unknown vectors. NOTE: the previous information was obtained from the March 2010 CPU. Oracle has not commented on claims from a reliable researcher that this is due to missing privilege checks during deserialization of RMIConnectionImpl objects, which allows remote attackers to call system-level Java functions via the ClassLoader of a constructor that is being deserialized.
See the 
CVE page on Mitre.org
for more details.
