The moxa char driver is missing a CAP_SYS_RAWIO check which could allow a local
user the ability to do things like replace the firmware.  This is already fixed
in 2.4-bk and in 2.6.10-ac7 from Alan Cox (although it's ommitted from 2.6.10-ac10).

Patch available:
http://linux.bkbits.net:8080/linux-2.4/cset@41e2c5fb3htiRRycYu5I4skGWXcv5g

There is a rumour that moxa doesn't work with 2.6 at all, so it may not affect
RHEL4, please let us know if this is the case.