In Eclipse OpenJ9 prior to version 0.21 on Power platforms, calling the System.arraycopy method with a length longer than the length of the source or destination array can, in certain specially crafted code patterns, cause the current method to return prematurely with an undefined return value. This allows whatever value happens to be in the return register at that time to be used as if it matches the method's declared return type.

From Eclipse OpenJ9 0.15 to 0.16, access to diagnostic operations such as causing a GC or creating a diagnostic file are permitted without any privilege checks.

All builds of Eclipse OpenJ9 prior to 0.15 contain a bug where the loop versioner may fail to privatize a value that is pulled out of the loop by versioning - for example if there is a condition that is moved out of the loop that reads a field we may not privatize the value of that field in the modified copy of the loop allowing the test to see one value of the field and subsequently the loop to see a modified field value without retesting the condition moved out of the loop. This can lead to a variety of different issues but read out of array bounds is one major consequence of these problems.

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 0.11.0, the OpenJ9 JIT compiler may incorrectly omit a null check on the receiver object of an Unsafe call when accelerating it.

In OpenJDK + Eclipse OpenJ9 version 0.11.0 builds, the public jdk.crypto.jniprovider.NativeCrypto class contains public static natives which accept pointer values that are dereferenced in the native 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.