A flaw was found in the way the JSSE component in OpenJDK performed X.509 certificate identify verification when establishing TLS/SSL connection to a host identified using IP address. In certain cases, it would incorrectly use a host name obtained after performing reverse DNS lookup of the specified IP address rather than the original IP address for the identity check, possibly leading to having a certificate issued for different identity to be accepted as valid.

This issue is know to affect cases when SSLSocketFactory.createSocket() is called with certain InetAddress instances. It is not known to affect cases when target host IP is passed to createSocket() as string, or when IP is used in URL used for HttpsURLConnection.

With this patch, reverse DNS lookup is no longer performed. The fix also adds new system property jdk.tls.trustNameService that can be used to allow the DNS lookup to be performed and hence have its result used during identity check.