OS Security Basics & Unix Access Control
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Software User Guide
Software User Guide • For the safe use of your camera, be sure to read the “Safety Precautions” thoroughly before use. • Types of software installed on your computer varies depending on the method of installation from the Caplio Software CD-ROM. For details, see the “Camera User Guide”. Using These Manuals How to Use the The two manuals included are for your Caplio Software User Guide 500SE. Display examples: 1. Understanding How to Use Your The LCD Monitor Display examples may be Camera different from actual display screens. “Camera User Guide” (Printed manual) Terms: This guide explains the usage and functions In this guide, still images, movies, and sounds of the camera. You will also see how to install are all referred to as “images” or “files”. the provided software on your computer. Symbols: This guide uses the following symbols and conventions: Caution Caution This indicates important notices and restrictions for using this camera. 2. Downloading Images to Your Computer “Software User Guide” Note *This manual (this file) This indicates supplementary explanations and useful This guide explains how to download images tips about camera operations. from the camera to your computer using the provided software. Refer to This indicates page(s) relevant to a particular function. “P. xx” is used to refer you to pages in this manual. Term 3. Displaying Images on Your This indicates terms that are useful for understanding Computer the explanations. The provided software “ImageMixer” allows you to display and edit images on your computer. For details on how to use ImageMixer, click the [?] button on the ImageMixer window and see the displayed manual. -
End-User Computing Security Guidelines Previous Screen Ron Hale Payoff Providing Effective Security in an End-User Computing Environment Is a Challenge
86-10-10 End-User Computing Security Guidelines Previous screen Ron Hale Payoff Providing effective security in an end-user computing environment is a challenge. First, what is meant by security must be defined, and then the services that are required to meet management's expectations concerning security must be established. This article examines security within the context of an architecture based on quality. Problems Addressed This article examines security within the context of an architecture based on quality. To achieve quality, the elements of continuity, confidentiality, and integrity need to be provided. Confidentiality as it relates to quality can be defined as access control. It includes an authorization process, authentication of users, a management capability, and auditability. This last element, auditability, extends beyond a traditional definition of the term to encompass the ability of management to detect unusual or unauthorized circumstances and actions and to trace events in an historical fashion. Integrity, another element of quality, involves the usual components of validity and accuracy but also includes individual accountability. All information system security implementations need to achieve these components of quality in some fashion. In distributed and end-user computing environments, however, they may be difficult to implement. The Current Security Environment As end-user computing systems have advanced, many of the security and management issues have been addressed. A central administration capability and an effective level of access authorization and authentication generally exist for current systems that are connected to networks. In prior architectures, the network was only a transport mechanism. In many of the systems that are being designed and implemented today, however, the network is the system and provides many of the security services that had been available on the mainframe. -
CSC 405 Computer Security Linux Security
CSC 405 Computer Security Linux Security Alexandros Kapravelos [email protected] Unix / Linux • Started in 1969 at AT&T / Bell Labs • Split into a number of popular branches – BSD, System V (commercial, AT&T), Solaris, HP-UX, AIX • Inspired a number of Unix-like systems – Linux, Minix • Standardization attempts – POSIX, Single Unix Specification (SUS), Filesystem Hierarchy Standard (FHS), Linux Standard Base (LSB), ELF OS Security • Kernel vulnerability – usually leads to complete system compromise – attacks performed via system calls Kernel vulnerabilities Kernel vulnerabilities Kernel exploitation research is active Unleashing Use-Before-Initialization Vulnerabilities in the Linux Kernel Using Targeted Stack Spraying • reliably exploiting uninitialized uses on the kernel stack has been considered infeasible • code executed prior to triggering the vulnerability must leave an attacker-controlled pattern on the stack • a fully automated targeted stackspraying approach for the Linux kernel that reliably facilitates the exploitation of uninitialized uses • published in NDSS 2017 source: https://www.cc.gatech.edu/~klu38/publications/ubi-ndss17.pdf Unix • Code running in user mode is always linked to a certain identity – security checks and access control decisions are based on user identity • Unix is user-centric – no roles • User – identified by username (UID), group name (GID) – typically authenticated by password (stored encrypted) • User root – superuser, system administrator – special privileges (access resources, modify OS) – cannot -
Student Computer User Agreement
STUDENT COMPUTER USER AGREEMENT GUIDING PRINCIPLE OF THIS AGREEMENT: Lakeside’s technological resources are dedicated to further the school’s mission and to serve the educational pursuits of its students. Students using Lakeside’s technology services are expected to behave in accordance with the Community Expectations documented in the family handbook. Students are expected to act in ways that show consideration and respect for other people and enhance an open atmosphere of trust, both offline and online. TECHNOLOGY SERVICES The use of Lakeside’s technology services – tech support, network access, email accounts, storage services, software subscriptions and all other school-owned computer resources – is a privilege, not a right. This privilege may be revoked at any time for abusive conduct, or failure to abide by the school’s expectations and/or responsible usage listed below. GENERAL EXPECTATIONS ▪ Lakeside email accounts, software and services, and onsite network access are provided primarily for school-related work. ▪ Any user of Lakeside’s electronic communications resources is expected to respect the person and privacy of others. ▪ The configuration of school-issued computers (operating system, security settings and software applications) may not be altered. ▪ Using the Lakeside computer network to exchange or store pirated software, unlawful information, or other unauthorized copyright-protected material (i.e. music, multimedia) in any file format is strictly prohibited. ▪ Students are expected to maintain the integrity of their computing devices so as not to bring viruses, malware or spyware to school. Unprotected and infected devices are forbidden to connect to the school network and, when detected, will be disconnected from the network until resolved. -
Environment Variable and Set-UID Program Lab 1
SEED Labs – Environment Variable and Set-UID Program Lab 1 Environment Variable and Set-UID Program Lab Copyright © 2006 - 2016 Wenliang Du, All rights reserved. Free to use for non-commercial educational purposes. Commercial uses of the materials are prohibited. The SEED project was funded by multiple grants from the US National Science Foundation. 1 Overview The learning objective of this lab is for students to understand how environment variables affect program and system behaviors. Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer. They are used by most operating systems, since they were introduced to Unix in 1979. Although environment variables affect program behaviors, how they achieve that is not well understood by many programmers. As a result, if a program uses environment variables, but the programmer does not know that they are used, the program may have vulnerabilities. In this lab, students will understand how environment variables work, how they are propagated from parent process to child, and how they affect system/program behaviors. We are particularly interested in how environment variables affect the behavior of Set-UID programs, which are usually privileged programs. This lab covers the following topics: • Environment variables • Set-UID programs • Securely invoke external programs • Capability leaking • Dynamic loader/linker Readings and videos. Detailed coverage of the Set-UID mechanism, environment variables, and their related security problems can be found in the following: • Chapters 1 and 2 of the SEED Book, Computer & Internet Security: A Hands-on Approach, 2nd Edition, by Wenliang Du. -
SETUID Programming Due: February 15, 2017
CSC 482/582 Assignment #3 (100 points) SETUID Programming Due: February 15, 2017 1 Introduction The learning objective of this assignment is for students to understand how environment variables affect program and system behaviors. Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer. They are used by most operating systems, including Unix and Windows. Although environment variables affect program behaviors, how they achieve that is not well understood by many programmers. Therefore, if a program uses environment variables, but the programmer do not know that they are used, the program may have vulnerabilities. In this assignment, students will learn how environment variables work, how they are propogated from parent process to child, and how they affect system/program bahivors. We are particularly interested in how environment variables affect the behavior of SETUID programs, which are usually privileged programs. SETUID is an important security mechanism in Unix operating systems. When a regular program is run, it runs with the privilege of the user executing that program. When a SETUID program is run, it runs with the privilege of the program file owner. For example, if the program’s owner is root, then when anyone runs this program, the program gains root’s privileges during its execution. SETUID allows us to perform essential tasks, such as changing passwords, but vulnerabilities in SETUID programs can allow an adversary to perform local privilege escalation. While the SETUID concept is limited to Unix, the problems of dangerous environment variables and local privilege escalation exists on all operating systems. -
The Management of End User Computing a Research Perspective
HD2 8 .M414 Oe>NeV THE MANAGEMENT OF END USER COMPUTING A RESEARCH PERSPECTIVE John F. Rockart Lauren S. Flannery February 1983 CISR WP #100 Sloan WP // 1410-83 Centerfor Information Systems Research Massachusetts Institute of Technology Sloan School of Management 77 Massachusetts Avenue Cambridge, Massachusetts, 02139 THE MANAGEMENT OF END USER COMPUTING A RESEARCH PERSPECTIVE John F. Rockart Lauren S . Flannery February 1983 CISR WP #100 Sloan WP // 1410-83 Rockart - Flannery 1983 Center for Information Systems Research Sloan School of Management Massachusetts Institute of Technology MAY 3 1 1983 RECe;v£d 1- ABSTRACT Based on interviews with 200 end users and 50 information systems managers concerned with end user computing, end users can be classified into six distinct types. Each of them needs differentiated education, support and control from the Information Systems function. End users exist primarily in staff functions. They develop and use a wide spectrum of computing applications ranging from "operational systems" of the type usually developed by information systems professionals to complex analytical programs. To support a large number of their applications a new computing environment, "the third environment" (in addition to the traditional COBOL and timesharing environments) must be developed by Information Systems (I/S) management. Close attention must also be paid by I/S management to the need to involve "functional support personnel" (end users in each functional area who spend most of their time programming and aiding other end users) in the I/S end user management process. An end user strategy is needed in each organization. In addition, users cite increasing needs for support from I/S management. -
Least Privilege and Privilege Separation
CSE 127: Computer Security Least privilege and privilege separation Deian Stefan Slides adopted from John Mitchell, Dan Boneh, and Stefan Savage This week… • How to build secure systems ➤ Least privilege and privilege separation ➤ Sandboxing and isolation • Key is underlying principles not mechanisms ➤ We’re going to look at systems techniques ➤ Other ways to achieve similar goals: language-based Principles of secure design • Principle of least privilege • Privilege separation • Defense in depth ➤ Use more than one security mechanism ➤ Fail securely/closed • Keep it simple Principles of secure design • Principle of least privilege • Privilege separation • Defense in depth ➤ Use more than one security mechanism ➤ Fail securely/closed • Keep it simple Principle of Least Privilege Defn: A system should only have the minimal privileges needed for its intended purposes • What’s a privilege? ➤ Ability to access (e.g., read or write) a resource Principle of Least Privilege Defn: A system should only have the minimal privileges needed for its intended purposes • What’s a privilege? ➤ Ability to access (e.g., read or write) a resource Principle of Least Privilege Defn: A system should only have the minimal privileges needed for its intended purposes • What’s a privilege? ➤ Ability to access (e.g., read or write) a resource What’s the problem with this defn? • Talking about a huge, monolith system is not really useful • Why? Network Network User input User device File system File system Breaking a system into components • Compartmentalization and isolation ➤ Separate the system into isolated compartments ➤ Limit interaction between compartments • Why is this more meaningful? Network Network User input User device File system File system How dow we break things apart? Map compartment to user ids! • Recall: permissions in UNIX granted according to UID ➤ A process may access files, network sockets, …. -
Linux Networking Cookbook.Pdf
Linux Networking Cookbook ™ Carla Schroder Beijing • Cambridge • Farnham • Köln • Paris • Sebastopol • Taipei • Tokyo Linux Networking Cookbook™ by Carla Schroder Copyright © 2008 O’Reilly Media, Inc. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (safari.oreilly.com). For more information, contact our corporate/institutional sales department: (800) 998-9938 or [email protected]. Editor: Mike Loukides Indexer: John Bickelhaupt Production Editor: Sumita Mukherji Cover Designer: Karen Montgomery Copyeditor: Derek Di Matteo Interior Designer: David Futato Proofreader: Sumita Mukherji Illustrator: Jessamyn Read Printing History: November 2007: First Edition. Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of O’Reilly Media, Inc. The Cookbook series designations, Linux Networking Cookbook, the image of a female blacksmith, and related trade dress are trademarks of O’Reilly Media, Inc. Java™ is a trademark of Sun Microsystems, Inc. .NET is a registered trademark of Microsoft Corporation. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and O’Reilly Media, Inc. was aware of a trademark claim, the designations have been printed in caps or initial caps. While every precaution has been taken in the preparation of this book, the publisher and author assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. -
Secure Automation: Achieving Least Privilege with SSH, Sudo and Setuid Robert A
Secure Automation: Achieving Least Privilege with SSH, Sudo and Setuid Robert A. Napier – Cisco Systems ABSTRACT Automation tools commonly require some level of escalated privilege in order to perform their functions, often including escalated privileges on remote machines. To achieve this, developers may choose to provide their tools with wide-ranging privileges on many machines rather than providing just the privileges required. For example, tools may be made setuid root, granting them full root privileges for their entire run. Administrators may also be tempted to create unrestricted, null-password, root-access SSH keys for their tools, creating trust relationships that can be abused by attackers. Most of all, with the complexity of today’s environments, it becomes harder for administrators to understand the far-reaching security implications of the privileges they grant their tools. In this paper we will discuss the principle of least privilege and its importance to the overall security of an environment. We will cover simple attacks against SSH, sudo and setuid and how to reduce the need for root-setuid using other techniques such as non-root setuid, setgid scripts and directories, sudo and sticky bits. We will demonstrate how to properly limit sudo access both for administrators and tools. Finally we will introduce several SSH techniques to greatly limit the risk of abuse including non-root keys, command keys and other key restrictions. Introduction to files writable only by a particular group. For exam- ple, in FreeBSD programs that read system memory Since its introduction in 1995 by Tatu Ylonen, are setgid to a special kmem group. -
(Malicious Software) Installed on Your Computer Without Your Consent to Monitor Or Control Your Computer Use
Spyware is a type of malware (malicious software) installed on your computer without your consent to monitor or control your computer use. Clues that spyware is on a computer may include a barrage of pop-ups, a browser that takes you to sites you don't want, unexpected toolbars or icons on your computer screen, keys that don't work, random error messages, and sluggish performance when opening programs or saving files. In some cases, there may be no symptoms at all. While the term spyware suggests that software that secretly monitors the user's computing, the functions of spyware extend well beyond simple monitoring. Spyware programs can: Collect information stored on the computer or attached network drives, Collect various types of personal information, such as Internet surfing habits, sites that have been visited Collect user names and passwords stored on your computer as well as those entered from the keyboard. Interfere with user control of the computer Install additional software on the computer Redirect Web browser activity. Change computer settings, resulting in slow connection speeds, different home pages, and/or loss of Internet or functionality of other programs. The best defense against spyware and other unwanted software is not to download it in the first place. Here are a few helpful tips that can protect you from downloading software you don't want: Update your operating system and Web browser software, and set your browser security high enough to detect unauthorized downloads. Use anti-virus and anti-spyware, as well as a firewall software, and update them all regularly. -
ICU Medical Mednet™ Software User Guide
Software User Guide For a list of ICU Medical MedNet compatible devices approved by country, refer to the ICU Medical MedNet Device Compatibility Matrix available through your ICU Medical Technical Support. 430-98350-001 (%, 2017-) Notes: ICU Medical MedNet™ Software User Guide Rx Only 16037-92-01 IMPORTANT Refer to this guide for proper use, warnings, and cautions associated with the installation and upgrade of the ICU Medical MedNet™ Software performed by the ICU Medical Service Team. Please contact your sales representative for any questions associated with installing and configuring the ICU Medical MedNet™ Software. The help files included with the ICU Medical MedNet™ software are provided as reference only. Please read this entire guide before using the ICU Medical MedNet™ Software. Please also read the ICU Medical Release Notes before using the ICU Medical MedNet™ Software. Intended Use The ICU Medical MedNet™ Medication Management Suite (MMS) is intended to facilitate networked communication between MMS compatible computer systems and MMS compatible Infusion pumps. The MMS provides trained healthcare professionals with the capability to send, receive, report, and store information from interfaced external systems, and to configure and edit infusion programming parameters. The MMS is intended to provide a way to automate the programming of infusion parameters, thereby decreasing the amount of manual steps necessary to enter infusion data. All data entry and validation of infusion parameters is performed by a trained healthcare professional