Apache WSS4J 1.6.5 contained a countermeasure for Bleichenbacher's attack on XML Encryption, where the PKCS#1 v1.5 Key Transport Algorithm is used to encrypt symmetric keys as part of WS-Security. In particular, the fix avoided leaking information on whether decryption failed when decrypting the encrypted key or decrypting the message data.

However, it is still possible to craft a message such that an attacker can tell where the decryption failure took place, and hence WSS4J is vulnerable to the original attack.

See here for more information on the original fix for WSS4J 1.6.5:

http://cxf.apache.org/note-on-cve-2011-2487.html https://bugzilla.redhat.com/showbug.cgi?id=CVE-2011-2487

This has been fixed in revision:

http://svn.apache.org/viewvc?view=revision&revision=1621329