Re: rpc.ypupdated

[jml4 () cus cam ac uk (John Line)]

>   I've fixed the SunOS 4.1.3 ypupdated bug (I think). Using tcp_wrapper tcpd
> to call rpc.ypupdated by inetd, and restricting access for local domain machines,
> has blocked this security gap. Here follows the steps:
> ...
>  3) Create the file /etc/hosts.deny with the entry:
>
>    rpc.ypupdated : ALL : (/usr/ucb/finger -l @%h | /usr/ucb/mail -s %d-%h root) &

Er... what if the remote site's fingerd returns output which uses UCB mail's
~-escapes to run commands, or amend the headers and mail "interesting" files
somewhere? [I don't think I'll stick my neck out in this forum and risk
any suggestions about better ways to send the mail! :-)]

                                John Line
--
John Line - Cambridge University Computing Service, Computer Laboratory,
            New Museums Site, Pembroke Street, Cambridge CB2 3QG, England.
Internet: jml4 () cus cam ac uk  JANET: jml4 () uk ac cam cus  Phone: +44 1223 334708