Item Duplication Bug

atuday

Discussion Title - Item duplication by means of request duplication.

Description
Able to dupe items by sending multiple of the same item move from person to storage at the same time while spiking latency.

Bug Reproduction Steps
During periods of increased latency or when forcing my latency to increase through network manipulation I am able to spam multiple item move requests from my system to the server. Networking tools were used to reliably replicate this action reliably. During periods of high server latency it is possible to dupe items with inconsistency.

Expected Result
Item is moved from inventory to storage.

Bug Report - Actual Result
Item does not move out of inventory while multiple of item begins to appear in storage. Relogging results in item disappearing from inventory while multiple of that item remain in storage. Stackable items my then be combined and moved back into inventory.

This exploit requires behaviors that could be detected by anti cheat to replicate intentionally. Recommended actions, review of how server handles item transfers. Examination of anti cheat behavior tracking.