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