Published: 19 October 2010
Unspecified vulnerability in the Networking component in Oracle Java SE and Java for Business 6 Update 21, 5.0 Update 25, 1.4.2_27, and 1.3.1_28 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.
From the Ubuntu security team
It was discovered that the HttpURLConnection class did not validate request headers set by java applets, which could allow an attacker to trigger actions otherwise not allowed to HTTP clients.
red hat description: HttpURLConnection did not validate request headers set by applets, which could allow remote attackers to trigger actions otherwise restricted to HTTP clients.