Unknown | 70 lines | 70 code | 0 blank | 0 comment | 0 complexity | a545736e190c456ff90f31c6eb476854 MD5 | raw file
1.\" Copyright (c) 1985 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)6.t 5.1 (Berkeley) 4/17/91 33.\" 34.ds RH Security Tightening 35.NH 36Security Tightening 37.PP 38Since we do not wish to encourage rampant system cracking, 39we describe only briefly the changes made to enhance security. 40.NH 2 41Generic Kernel 42.PP 43Several loopholes in the process tracing facility have been corrected. 44Programs being traced may not be executed; 45executing programs may not be traced. 46Programs may not provide input to terminals to which they do not 47have read permission. 48The handling of process groups has been tightened to eliminate 49some problems. 50When a program attempts to change its process group, 51the system checks to see if the process with the pid of the process 52group was started by the same user. 53If it exists and was started by a different user the process group 54number change is denied. 55.NH 2 56Security Problems in Utilities 57.PP 58Setuid utilities no longer use the \fIpopen\fP or \fIsystem\fP library routines. 59Access to the kernel's data structures through the kmem device 60is now restricted to programs that are set group id ``kmem''. 61Thus many programs that used to run with root privileges 62no longer need to do so. 63Access to disk devices is now controlled by an ``operator'' group id; 64this permission allows operators to function without being the super-user. 65Only users in group wheel can do ``su root''; this restriction 66allows administrators to define a super-user access list. 67Numerous holes have been closed in the shell to prevent 68users from gaining privileges from set user id shell scripts, 69although use of such scripts is still highly discouraged on systems 70that are concerned about security.