In Eclipse OpenJ9 prior to 0.15, the String.getBytes(int, int, byte[], int) method does not verify that the provided byte array is non-null nor that the provided index is in bounds when compiled by the JIT. This allows arbitrary writes to any 32-bit address or beyond the end of a byte array within Java code run under a SecurityManager.
In Eclipse OpenJ9 prior to the 0.14.0 release, the Java bytecode verifier incorrectly allows a method to execute past the end of bytecode array causing crashes. Eclipse OpenJ9 v0.14.0 correctly detects this case and rejects the attempted class load.
In Eclipse OpenJ9, prior to the 0.12.0 release, the jio_snprintf() and jio_vsnprintf() native methods ignored the length parameter. This affects existing APIs that called the functions to exceed the allocated buffer. This functions were not directly callable by non-native user code.
In Eclipse OpenJ9 version 0.8, users other than the process owner may be able to use Java Attach API to connect to an Eclipse OpenJ9 or IBM JVM on the same machine and use Attach API operations, which includes the ability to execute untrusted native code. Attach API is enabled by default on Windows, Linux and AIX JVMs and can be disabled using the command line option -Dcom.ibm.tools.attach.enable=no.