networking.c in Redis before 3.2.7 allows "Cross Protocol Scripting" because it lacks a check for POST and Host: strings, which are not valid in the Redis protocol (but commonly occur when an attack triggers an HTTP request to the Redis TCP port).
https://www.reddit.com/r/redis/comments/5r8wxn/redis_327_is_out_important_security_fixes_inside/
https://raw.githubusercontent.com/antirez/redis/3.2/00-RELEASENOTES
https://github.com/antirez/redis/commit/874804da0c014a7d704b3d285aa500098a931f50