Id Software » Quake 2i Server : Security Vulnerabilities, CVEs,

Quake 2 (Q2) server 3.20 and 3.21 allows remote attackers to obtain sensitive server cvar variables, obtain directory listings, and execute Q2 server admin commands via a client that does not expand "$" macros, which causes the server to expand the macros and leak the information, as demonstrated using "say $rcon_password."