barcode generator in vb.net 2005 IT Auditing: Using Controls to Protect Information Assets, Second Edition in Software

Print Quick Response Code in Software IT Auditing: Using Controls to Protect Information Assets, Second Edition

IT Auditing: Using Controls to Protect Information Assets, Second Edition
QR Generator In None
Using Barcode creation for Software Control to generate, create QR Code image in Software applications.
Recognizing Denso QR Bar Code In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
21 Ensure that the chown command cannot be used by users to compromise user accounts
QR-Code Drawer In C#
Using Barcode generator for VS .NET Control to generate, create Quick Response Code image in .NET applications.
Printing QR Code ISO/IEC18004 In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Quick Response Code image in ASP.NET applications.
The chown command allows users to transfer ownership of their files to someone else If a user can transfer an SUID file to another user, he or she then will be able to execute that file and become the user For example, if a user copies his or her shell, makes it SUID and world-executable, and then transfers ownership to root, then, by executing that file, the user becomes root
Make QR Code JIS X 0510 In VS .NET
Using Barcode printer for .NET framework Control to generate, create Denso QR Bar Code image in .NET applications.
Draw Quick Response Code In Visual Basic .NET
Using Barcode printer for .NET framework Control to generate, create QR Code image in .NET framework applications.
Many versions of Unix allow only the superuser to execute chown Many others do not allow SUID bits to be transferred to another user To determine whether these controls are in place on the machine you are auditing, perform the following in order: 1 Review the password file and determine where your shell is located (it probably will be something like /bin/csh or /usr/bin/sh) 2 Run the command cp <shell file name> ~/myshell to create a copy of your shell file in your home directory 3 Run the command chmod 4777 ~/myshell to make your new shell file SUID and world executable 4 Choose another user from the password file to transfer ownership to, preferably a fellow auditor 5 Run the command chown <new owner name> ~/myshell, which will attempt to transfer ownership of the file to another user 6 Run the command ls -l ~/myshell to see whether you transferred ownership successfully and, if so, whether the SUID bit also transferred 7 If the SUID bit transferred to another owner, execute the file by typing /myshell This will execute the shell 8 Run the command whoami This should show that you are now the other user and have taken over his or her account 9 If this happens, the system administrator will need to contact his or her vendor for a fix
Code 128 Generation In None
Using Barcode generator for Software Control to generate, create Code128 image in Software applications.
ANSI/AIM Code 39 Generator In None
Using Barcode maker for Software Control to generate, create Code39 image in Software applications.
22 Obtain and evaluate the default umask value for the server
Bar Code Encoder In None
Using Barcode creator for Software Control to generate, create bar code image in Software applications.
EAN128 Encoder In None
Using Barcode maker for Software Control to generate, create GTIN - 128 image in Software applications.
The umask determines what permissions new files and directories will have by default If the default umask is not set properly, users could inadvertently be giving group and/ or world access to their files and directories The default should be for files to be created securely Privileges then can be loosened based on need and conscious decisions by the users (as opposed to their being unaware that their new files and directories are not secure)
Barcode Creator In None
Using Barcode encoder for Software Control to generate, create barcode image in Software applications.
UPC-A Supplement 5 Creator In None
Using Barcode drawer for Software Control to generate, create UPC Code image in Software applications.
The default may be set in /etc/profile or in one of the files in /etc/skel However, the easiest test is often just to view the umask value for your own account because this usu-
International Standard Serial Number Maker In None
Using Barcode drawer for Software Control to generate, create ISSN - 10 image in Software applications.
Draw EAN 128 In Visual C#.NET
Using Barcode maker for VS .NET Control to generate, create EAN / UCC - 14 image in .NET applications.
7: Auditing Unix and Linux Operating Systems
Printing Matrix 2D Barcode In C#.NET
Using Barcode creator for .NET framework Control to generate, create Matrix Barcode image in .NET framework applications.
Generating Matrix Barcode In Java
Using Barcode maker for Java Control to generate, create Matrix 2D Barcode image in Java applications.
ally will be a representation of the default value for all new users This can be done using the umask command The umask basically subtracts privileges when files and directories are created using the modular format of file permissions and assuming that the default is for all files and directories to be created fully open (777 permissions) In other words, with a umask of 000, all new files and directories will be created with default permissions of 777 (777 minus 000), meaning full access for the owner, group, and world For example, if the umask is set to 027, it will result in the following default permissions for newly created files and directories:
Drawing Data Matrix In Java
Using Barcode generation for Android Control to generate, create Data Matrix image in Android applications.
Making Barcode In Java
Using Barcode creator for Eclipse BIRT Control to generate, create barcode image in Eclipse BIRT applications.
Normal default Minus the umask Default permissions on this server 777 027 750
Recognizing DataMatrix In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Recognize USS Code 128 In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
PART II
This provides full access to the owner, read and execute access to the group, and no access to the world At a minimum, the default system generally should be set to a value of 027 (group write and all world access removed) or 037 (group write/execute and all world access removed)
23 Examine the system s crontabs, especially root s, for unusual or suspicious entries
A cron executes a program at a preset time It is basically the Unix or Linux system s native way of letting you schedule jobs The crontab (short for cron table) contains all the crons scheduled on the system Crons can be used to create time bombs or to compromise the owning account For example, if an attacker managed to compromise a user s account, he or she could set up a cron that would copy the user s shell nightly and make it SUID and then delete this copy of the shell 15 minutes later The attacker then could regain access to the account daily during that time period, but security-monitoring tools would not detect it unless the tools happened to run in that 15-minute window An example of a time bomb would be a case where a system administrator is fired or quits and schedules a cron that crashes the system to run 6 months later
The crontabs should be located within directory /usr/spool/cron/crontabs or /var/ spool/cron/crontabs By performing the ls l command on this directory, you will be able to list the contents Each account with a crontab will have its own file in this directory The contents of these files can be viewed with the more command This will allow you to see the commands that are being executed and the schedule for that execution Based on file permissions, you may need the administrator to display the contents of the crontabs Also, depending on the level of your Unix knowledge, you may need the administrator s help in interpreting the contents of the files
Copyright © OnBarcode.com . All rights reserved.