BSD tty security, part 3: How to Fix It

[Sean Eric Fagan]

In article <128049 at tyrell.stgt.sub.org> rodney at tyrell.stgt.sub.org (Rodney Volz) writes:
>Sorry for interfering, but I really don't see the point in discussing
>"write". Write does not have any S-Bit, so if you e.g. choose to make
>write reject messages > 20 lines, I'll just compile my own write.

kithrup 1> l /bin/write $(tty)
---x--s--x   1 bin      terminal   54172 Jun 11 1990 /bin/write
crw--w----   1 sef      terminal   0,  2 May 02 18:15 /dev/tty03

Gee.  I see an SGID bit there.  SunOS needs an SGID write as well, as does
4.3bsd (I think).

-- 
Sean Eric Fagan  | "I made the universe, but please don't blame me for it;
sef at kithrup.COM  |  I had a bellyache at the time."
-----------------+           -- The Turtle (Stephen King, _It_)
Any opinions expressed are my own, and generally unpopular with others.