The blog post on http://slightlyrandombrokenthoughts.blogspot.com/2011/01/trusted-method-chaining-to-systemexit.html describes how to construct a trusted method chain that calls into System.exit . While it could be difficult to workaround the general problem of trusted method chains, an straightforward fix for this would be to * replace the System.exit call with throwing an IllegalArgumentException in com.sun.org.apache.bcel.internal.classfile.Utility.codeToString() so attackers would not be able anymore to shut down the JVM. Looks like Oracle hasn't urgent plans to fix this, so this security patch will need propagation upstream into OpenJDK code source.
FWIW, I can't see the problem code in the version of JAXP imported into OpenJDK 6 on 2013-05-17 or OpenJDK 7 on 2011-12-22 changeset: 73:3cda33454120 user: andrew date: Fri May 17 15:39:15 2013 +0100 summary: OPENJDK6-6: Include JAXP sources in main repository once again changeset: 286:d9891683fc16 parent: 280:26f5422f16af user: joehw date: Thu Dec 22 14:00:00 2011 -0800 summary: 7121110: JAXP 1.4.5 update 1 for 7u4