A flaw was found in JBoss web services where the services used a weak symmetric encryption protocol, PKCS#1 v1.5. An attacker could use this weakness in chosen-ciphertext attacks to recover the symmetric key and conduct further attacks.

Tibor Jager, Kenneth G. Paterson and Juraj Somorovsky have described XML encryption backwards compatibility attacks against various frameworks, including Apache CXF. An attacker can use these flaws to force a server to utilize insecure, legacy cryptosystems when secure cryptosystems are enabled on endpoints. This could expose flaws in the underlying legacy cryptosystems, such as CVE-2011-1096 and CVE-2011-2487. This flaw also affects the jbossws-native stack.