71 lines
3.4 KiB
Perl
71 lines
3.4 KiB
Perl
.\" Copyright (c) 1985 The Regents of the University of California.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)6.t 5.1 (Berkeley) 4/17/91
|
|
.\"
|
|
.ds RH Security Tightening
|
|
.NH
|
|
Security Tightening
|
|
.PP
|
|
Since we do not wish to encourage rampant system cracking,
|
|
we describe only briefly the changes made to enhance security.
|
|
.NH 2
|
|
Generic Kernel
|
|
.PP
|
|
Several loopholes in the process tracing facility have been corrected.
|
|
Programs being traced may not be executed;
|
|
executing programs may not be traced.
|
|
Programs may not provide input to terminals to which they do not
|
|
have read permission.
|
|
The handling of process groups has been tightened to eliminate
|
|
some problems.
|
|
When a program attempts to change its process group,
|
|
the system checks to see if the process with the pid of the process
|
|
group was started by the same user.
|
|
If it exists and was started by a different user the process group
|
|
number change is denied.
|
|
.NH 2
|
|
Security Problems in Utilities
|
|
.PP
|
|
Setuid utilities no longer use the \fIpopen\fP or \fIsystem\fP library routines.
|
|
Access to the kernel's data structures through the kmem device
|
|
is now restricted to programs that are set group id ``kmem''.
|
|
Thus many programs that used to run with root privileges
|
|
no longer need to do so.
|
|
Access to disk devices is now controlled by an ``operator'' group id;
|
|
this permission allows operators to function without being the super-user.
|
|
Only users in group wheel can do ``su root''; this restriction
|
|
allows administrators to define a super-user access list.
|
|
Numerous holes have been closed in the shell to prevent
|
|
users from gaining privileges from set user id shell scripts,
|
|
although use of such scripts is still highly discouraged on systems
|
|
that are concerned about security.
|