The MITRE CVE dictionary describes this issue as:
Unspecified vulnerability in the Networking component in Oracle Java SE and Java for Business 6 Update 21 and 5.0 Update 25 allows remote attackers to affect confidentiality, integrity, and availability via unknown vectors. NOTE: the previous information was obtained from the October 2010 CPU. Oracle has not commented on claims from a reliable downstream vendor that this is related to missing validation of request headers in the HttpURLConnection class when they are set by applets, which allows remote attackers to bypass the intended security policy.
Find out more about CVE-2010-3573 from the
MITRE CVE dictionary dictionary and