The version in question is 2.2.0.SP1

CertificateReaderInputStream can cause the certificate information within EntryInfo to be initialised before the JarVerifier has had the opportunity to initialise the certificates associated with its JarEntry, resulting in this information being ignored. This is a particular problem if the entry represents a class file as any subsequent attempt to define the class will not be associated with the correct certificate/signers, causing a SecurityException to be raised if classes from the same package have already been loaded.

The SecurityException will be similar to the following

java.lang.SecurityException: class "org.drools.spi.CompiledInvoker"'s signer information does not match signer information of other classes in the same package