In Eclipse OpenJ9 versions prior to 0.63.0, the JITServer component is vulnerable to a pre-authentication remote denial of service. When processing the initial 4-byte length field of an incoming TCP connection, an integer overflow in `MessageBuffer::computeRequiredCapacity()` causes the receiving compilation worker thread to enter an infinite loop consuming ~100% CPU. An unauthenticated remote attacker can exploit this by opening a small number of crafted TCP connections to exhaust the entire worker thread pool, silently halting compilation services for all connected client JVMs.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0