this version of sendmail tries to use sysconf() if the _SC_* macros
are defined in unistd.h. We have the macros but not
the function. A temporary "fix" has been made to avoid
the issue.
from Eric Allman <eric@vangogh.cs.berkeley.edu>:
>Subject: sendmail 8.1C out
...
>THIS IS AN URGENT FIX. There is a security problem in 8.1B (and
>apparently most vendor versions of sendmail) that permits a user
>to read any file on the system (don't ask, I won't go into details).
>It should be installed immediately.
...
> ======================================================================
>
> 8.1C/8.1B 93/06/27
> Serious security bug fix: it was possible to read any file on
> the system, regardless of ownership and permissions.
> If a subroutine returns a fully qualified address, return it
> immediately instead of feeding it back into rewriting.
> This fixes a problem with mailertable lookups.
> CONFIG: fix some M4 frotz (concat => CONCAT)
>
