Quake II server before R1Q2, as used in multiple products, allows remote attackers to cause a denial of service (application crash) via a modified client that asks the server to send data stored at a negative array offset, which is not handled when processing Configstrings and Baselines.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.