Pomelo v2.2.5 allows external control of critical state data. A malicious user input can corrupt arbitrary methods and attributes in template/game-server/app/servers/connector/handler/entryHandler.js because certain internal attributes can be overwritten via a conflicting name. Hence, a malicious attacker can manipulate internal attributes by adding additional attributes to user input.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-18954
• NetEase/pomelo#1149
• https://github.com/cl0udz/vulnerabilities/tree/master/pomelo-critical-state-manipulation