Espruino before 1.99 allows attackers to cause a denial of service (application crash) with a user crafted input file via a Buffer Overflow during syntax parsing because a check for '\0' is made for the wrong array element in jsvar.c.
https://github.com/espruino/Espruino/issues/1435
https://github.com/espruino/Espruino/commit/ce1924193862d58cb43d3d4d9dada710a8361b89