STIG User Guide

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Short Description

The STIG User Guide provides instructions for implementing compliance with the recommendations specified in the UNIX Se...

Description

STIG User Guide

iDX Release 3.1

March 27, 2012

STIG User Guide

i

Copyright © 2012 VT iDirect, Inc. All rights reserved. Reproduction in whole or in part without permission is prohibited. Information contained herein is subject to change without notice. The specifications and information regarding the products in this document are subject to change without notice. All statements, information, and recommendations in this document are believed to be accurate, but are presented without warranty of any kind, express, or implied. Users must take full responsibility for their application of any products. Trademarks, brand names and products mentioned in this document are the property of their respective owners. All such references are used strictly in an editorial fashion with no intent to convey any affiliation with the name or the product's rightful owner.

Document Name: UG_STIG User Guide iDX 3.1 Rev A_03272012.pdf Document Part Number: T0000435

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STIG User Guide

Revision History

The following table shows all revisions for this document. If you do not have the revision that applies to your release, or you are not sure, please contact iDirect.

Revision

Date Released

Reason for Change(s)

Who Updated?

A

03/27/2012

Revision A for iDX Release 3.1

JVespoli

STIG User Guide

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Contents

About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Intended Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contents Of This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Document Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

Configuring Hub Servers for UNIX STIG Compliance. . . . . . . . . . . . . 1 1. STIG Feature Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Installing the STIG package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Executing the iDirect STIG Scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Logs Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Backups of Files Replaced by the Patch Scripts . . . . . . . . . . . . . . . . . . . . . . . 3 6. Performing Manual Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Procedure 1: GEN000400, GEN000420 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Procedure 2: LNX00140 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Procedure 3: GEN001260 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

7. STIG Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. PDIs Not Enforced by iDirect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9. Explanation of Specific Open Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.1 CAT I Open Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.2 CAT II Open Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

10. Open Findings Fixed by the STIG Scripts . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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STIG User Guide

About This Guide

Purpose The STIG User Guide provides instructions for implementing compliance with the recommendations specified in the UNIX Security Technical Implementation Guide (STIG) on iDirect hub servers such as the NMS servers and protocol processor blades. iDirect strives to produce documentation that is technically accurate, easy to use, and helpful to our customers. Your feedback is welcomed! Send your comments to [email protected]

Intended Audience The STIG User Guide is intended for UNIX system administrators responsible for implementing the STIG feature on their iDirect UNIX servers.

Contents Of This Guide This document contains the following major sections: •

STIG Feature Overview



Installing the STIG package



Executing the iDirect STIG Scripts



Logs Directory



Backups of Files Replaced by the Patch Scripts



Performing Manual Updates



STIG Exceptions



PDIs Not Enforced by iDirect



Open Findings Fixed by the STIG Scripts

STIG User Guide

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Document Conventions This section illustrates and describes the conventions used throughout the user guide. Convention Description

Example

Blue Courier font

Used when the user is required to enter a command at a command line prompt or in a console.

Enter the command:

Courier font

Used when showing software code or output from a command that was entered at a command line or on a console.

rpm -qa | grep sendmail sendmail-devel-8.12.11-4.RHEL3.1 sendmail-8.12.11-4.RHEL3.1 sendmail-cf-8.12.11-4.RHEL3.1

Bold Trebuchet font

Used when referring to text that appears on the screen on a windows-type Graphical User Interface (GUI).

Launch PuTTY using iMonitor by right-clicking the blade in the Network Tree and selecting Connect.

service idirect_nms stop

Used when specifying names of commands, menus, folders, tabs, dialogs, list boxes, and options.

vi

Blue Trebuchet font

Used to show all hyperlinked text within a document.

See “Open Findings Fixed by the STIG Scripts” on page 17 for a list of the modifications made by the iDirect scripts.

Bold italic Trebuchet font

Used to emphasize information for the user, such as in notes.

Note:

Red italic Trebuchet font

Used when the user needs to strictly follow the instructions or have additional knowledge about a procedure or action.

WARNING! The following procedure may cause a

This procedure applies only to NMS server machines.

network outage.

STIG User Guide

STIG Feature Overview

Configuring Hub Servers for UNIX STIG Compliance

Security Technical Implementation Guides (STIGs) are checklists of recommended settings for various computer platforms. They define configuration standards for DOD Information Assurance (IA) and IA-enabled systems. The STIGs can be found at the Web site of the Information Assurance Support Environment (IASE), http://iase.disa.mil/. This document describes the iDirect STIG feature for compliance with the STIG recommendations applicable to the Linux operating environment deployed on iDirect hub servers. It contains the following major sections: •

“STIG Feature Overview” on page 1



“Installing the STIG package” on page 2



“Executing the iDirect STIG Scripts” on page 3



“Logs Directory” on page 3



“Backups of Files Replaced by the Patch Scripts” on page 3



“Performing Manual Updates” on page 4



“STIG Exceptions” on page 6



“PDIs Not Enforced by iDirect” on page 6



“Explanation of Specific Open Findings” on page 6



“Open Findings Fixed by the STIG Scripts” on page 10

Note:

1.

This version of the STIG User Guide applies only to iDirect hub servers running iDX Release 3.1.

STIG Feature Overview iDirect provides a set of scripts that you can run to modify your hub servers to meet many of the recommendations specified in the UNIX Security Checklist dated July, 2011. iDirect’s implementation addresses both general UNIX recommendations and Linux-specific recommendations documented in the Security Technical Implementation Guide (STIG). A STIG contains a list of security requirements for a specific operating environment. Each security requirement is identified by a Potential Discrepancy Item (PDI). A PDI consists of a Short Description Identifier (SDID) and a severity code.

STIG User Guide

1

Installing the STIG package

Results of the STIG installation are written to log files, which you can then examine to verify that the changes were properly applied to the system. The procedure for installing the package on your hub servers is contained in “Installing the STIG package” on page 2. The format of the log files is specified in “Logs Directory” on page 3. In addition to the STIG recommendations that are automatically applied by the scripts, iDirect supports a number of manual configuration changes to meet additional STIG recommendations. Instructions for manually applying these additional changes are contained in “Performing Manual Updates” on page 4. Some STIG recommendations are either not applicable to the iDirect system or are the direct responsibility of your Security Administrator (SA). These recommendations are listed in the section “PDIs Not Enforced by iDirect” on page 6.

2.

Note:

Several UNIX STIG recommendations cannot be implemented on iDirect servers because meeting those recommendations would interfere with iDirect system operation. These recommendations are listed as exceptions in the STIG log. See “STIG Exceptions” on page 6 for a list of PDIs not supported by iDirect systems.

Note:

Since STIG recommendations are continually changing, there is a strong possibility that you will discover issues not discussed in this document when conducting evaluations against later versions of the UNIX STIG. Please report all such findings to the iDirect TAC so that iDirect can determine whether or not these issues can be addressed in future updates to the STIG feature.

Installing the STIG package You can automatically install the STIG package and execute the iDirect STIG scripts when you upgrade to, or perform a new installation of, this release. •

If you installed your iDirect release using a security enhanced Kickstart option (for example, SE-NMS or SE-Protocol Processor) then the STIG package was automatically installed and the STIG scripts were automatically executed during the installation.



You can upgrade a non-STIG server to a STIG server by executing the idsUpdate script with the --harden and --force options. For example: mkdir -p /media/cdrom mount /dev/cdrom /media/cdrom /media/cdrom/iDirect/install/idsUpdate --harden --force eject



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You can upgrade a server with STIG already installed by the executing the idsUpdate script with the --harden option. The --force option is not required.

Note:

When using the --force option, the --harden option is also required.

Note:

In order to remain STIG compliant you should pass the --harden option to idsUpdate whenever you upgrade to a new iDirect release.

Note:

For more information, see the Network Upgrade Procedure or Software Installation Guide for your iDX Release.

STIG User Guide

Executing the iDirect STIG Scripts

3.

Executing the iDirect STIG Scripts The procedure in this section executes the iDirect STIG scripts. You can run the iDirect scripts at any time. For example, you may want to re-run the scripts after making changes to your system. Follow these steps to execute the iDirect STIG scripts: 1. Log on to the root account of the server on which you want to execute the STIG scripts. 2. On an NMS server, ensure that all NMS and mysql services are stopped by entering the commands: service idirect_nms stop service mysql stop 3. From the command line of the root account, change to the STIG directory by entering the command: cd /opt/stig 4. Enter the following command to run the STIG scripts: ./idirect_stig The results are displayed to the user. When you run the iDirect scripts, the operating environment is updated to meet the STIG recommendations. Note:

4.

Once you have run the STIG scripts or performed the manual updates documented on page page 4, you must reboot the server.

Logs Directory Results of the iDirect STIG scripts are written to the following directory: /opt/stig/logs/ Each time you run the iDirect STIG scripts, the results are logged in a new file in that directory with the name: .log where is the date and time that the STIG scripts were executed. The STIG log files contain detailed output for each PDI fixed by the iDirect STIG scripts, including all changes made to the system.

5.

Backups of Files Replaced by the Patch Scripts Whenever a file is replaced by the iDirect patch scripts, the original file is copied to the following directory: /opt/stig/bak Each file is backed up to a subdirectory of /opt/stig/bak that includes the full path of the original file and a timestamp indicating when the file was backed up.

STIG User Guide

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Performing Manual Updates

For example, if a script modifies the file /etc/ssh/sshd_config, the backup of that file is written to the following directory: /opt/stig/bak/etc/ssh/sshd_config. where represents the date and time that the file was backed up.

6.

Performing Manual Updates This section describes manual configuration changes that you can make on your iDirect Linux servers to comply with a number of PDIs not addressed by the iDirect scripts. These procedures correct a number of open findings that remain outstanding after the iDirect scripts have been executed. Note:

There are some open findings that cannot be addressed on iDirect servers. See “STIG Exceptions” on page 6 for a list of PDIs associated with these findings.

Follow the procedures in this section to make your server compliant with the specified PDIs. Each procedure consists of one or more PDIs and the steps required to modify the server configuration to comply with those PDIs. Note:

After you have made these changes, be sure to reboot your server.

Procedure 1: GEN000400, GEN000420 (GEN000400: CAT II) (Previously – G010) The SA will ensure a logon-warning banner is displayed on all devices and sessions at the initial logon. (GEN000420: CAT II) (Previously – G011) The IAO will ensure the Legal Notice Logon Warning Banner includes the five points outlined in the CJCSM 6510.01. All DOD AISs will display, as a minimum, an electronic logon notice and consent banner that advises users of the following principles: - The system is a DOD system. - The system is subject to monitoring. - Monitoring is authorized in accordance with applicable laws and regulations and conducted for purposes of systems management and protection, protection against improper or unauthorized use or access, and verification of applicable security features or procedures. - Use of the system constitutes consent to monitoring. - This system is for authorized US government use only. Follow the below steps to modify the login banner: 1. Edit the file /etc/motd. 2. Enter the content to comply with the PDI requirements. 3. Save the changes to /etc/motd.

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STIG User Guide

Performing Manual Updates

Procedure 2: LNX00140 (LNX00140: CAT I) The GRUB boot-loader does not use an MD5 encrypted password. Follow these steps to comply with the above PDI: 1. From the command line, enter the following command: grub-md5-crypt 2. When prompted, enter the password to obtain the password hash. Sample output is shown here: Password: Retype password: $1$aKQ1L/$Hc0lGPZcI/MoWSc0Tcag31 3. Add the password hash to the grub configuration file /boot/grub/grub.conf as shown in the example below: default=0 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu password --md5 $1$aKQ1L/$Hc0lGPZcI/MoWSc0Tcag31 title Red Hat Enterprise Linux Server (2.6.18-164.6.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-164.6.1.el5 ro root=LABEL=/ initrd /initrd-2.6.18-164.6.1.el5.img

Procedure 3: GEN001260 (GEN001260: CAT II) System log file permissions are more permissive than 640. Follow the steps below to comply with the above PDI: 1. Find all files with permissions greater than 640 in the directory /var/log: find /var/log -perm /137 -ls 2. For every log file found in Step 1 (after determining that the log file's permissions can be safely changed) modify the file permissions using the following command: chmod 640 Where is the name of the log file. Note:

STIG User Guide

Due to the fact that log files can be created from many different processes that are not under iDirect’s control, iDirect cannot ensure 100% automated compliance with GEN001260. Upon execution, to the extent possible, the iDirect STIG hardening scripts set the permissions on existing log files properly and change the configuration options for future log files to comply with this PDI. However, there is no guarantee that new log files, rotated log files, or log configuration options will have or maintain the proper permissions. See the UNIX Security Checklist for more details.

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STIG Exceptions

7.

STIG Exceptions iDirect servers are not compliant with the PDIs listed in this section. Complying with the PDIs in this list will interfere with the normal operations of iDirect networks. For complete definitions of these PDIs, see the UNIX Security Technical Implementation Guide. Note:

iDirect does not support customer updates of any Operating System installed software. For example, customer upgrades to openssl or any other software package are not supported. Table 1. List of UNIX STIG PDIs Not Supported on iDirect Servers

PDI Exceptions

Description

GEN000120

Vendor Recommended and Security Patches are not installed or are out-ofdate.

GEN000760

An account is not locked after 35 days of inactivity.

GEN001560*

User directories contain undocumented non-startup files with access permissions greater than 750.

GEN006640

An approved DoD virus scan program is not used and/or updated.

*GEN001560 is an exception only on the NMS server, not on the protocol processor blades.

8.

PDIs Not Enforced by iDirect Not all PDIs are directly enforced on iDirect systems as part of the STIG feature. Some unenforced PDIs are not applicable to iDirect servers. Others describe policies, periodic procedures, or utilities (such as auditing tools) that are the responsibility of the Security Administrator (SA) and are therefore outside of the scope of the iDirect STIG feature. You are free to enforce these PDIs as required by your policies. For definitions of PDIs that are the responsibility of the SA, see the UNIX Security Technical Implementation Guide. The PDIs discussed here differ from the PDI exceptions listed in “STIG Exceptions” on page 6, since compliance with the exceptions would interfere with normal operations of iDirect systems.

9.

Explanation of Specific Open Findings This section provides an explanation of a number of open findings not fixed by the iDirect scripts. These open findings may appear after running the STIG scripts. Only CAT I and CAT II open findings are documented.

9.1

CAT I Open Findings

2001-A-0013: Ssh is vulnerable to a remote integer overflow. Resolution: False Positive

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STIG User Guide

Explanation of Specific Open Findings

Vulnerable Systems: • OpenSSH 1.2, 1.2.1 - 1.2.3 •

OpenSSH 2.1, 2.1.1, 2.2.0

The version of openssh we provide is greater than or equal to 4.3p2-41.el5.

2002-T-0011: There are vulnerabilities in the OpenSSH Challenge Response Handling routine. Resolution: False Positive Vulnerable Systems: • OpenSSH: Versions 2.3.1p1 through version 3.3 are vulnerable. The version of openssh we provide is greater than or equal to 4.3p2-41.el5.

2003-A-0015: There are multiple vulnerabilities in OpenSSL. Resolution: False Positive Vulnerable Systems: • OpenSSL Project OpenSSL 0.9.6 •

OpenSSL Project OpenSSL 0.9.6 a



OpenSSL Project OpenSSL 0.9.6 b



OpenSSL Project OpenSSL 0.9.6 c



OpenSSL Project OpenSSL 0.9.6 d



OpenSSL Project OpenSSL 0.9.6 e



OpenSSL Project OpenSSL 0.9.6 g



OpenSSL Project OpenSSL 0.9.6 h



OpenSSL Project OpenSSL 0.9.6 i



OpenSSL Project OpenSSL 0.9.6 j



OpenSSL Project OpenSSL 0.9.7



OpenSSL Project OpenSSL 0.9.7 a



OpenSSL Project OpenSSL 0.9.7 b



OpenSSL Project OpenSSL 0.9.7 beta1



OpenSSL Project OpenSSL 0.9.7 beta2



OpenSSL Project OpenSSL 0.9.7 beta3

The version of openssl we provide is greater than or equal to 0.9.8e-12.el5_4.6.

2009-T-0024: Multiple Vulnerabilities in Linux Kernel. Resolution: False Positive The Unix Checklist states: Compliance Checking: Red Hat Enterprise Linux 3 is vulnerable to CVE-2009-1265. RHEL4 and RHEL5 are not. However, this IAVA does cover more than one CVE. A response from the Red Hat Knowledge base indicates RHEL3 will not be patched and it will always be a finding on

STIG User Guide

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Explanation of Specific Open Findings

the system. RHEL4 does not appear to have any fixes, so this will be a finding. Execute uname -a to determine the kernel version. RHEL5 does have a kernel update for the CIFS vulnerability. If the kernel version is less than 2.6.18-128.1.14.el5, this is a finding. The kernel version we provide is greater than 2.6.18-128.1.14.el5.

2010-A-0041: Multiple Apache HTTP Server Vulnerabilities Resolution: False Positive CVE-2010-0408 Fixed by Red Hat in version 2.2.3-31.el5_4.4 or later. We provide a later release. Source: https://rhn.redhat.com/errata/RHSA-2010-0168.html

2010-A-0050: OpenSSL Remote Denial of Service Vulnerability. Resolution: False Positive CVE-2010-0740 Official Statement from Red Hat (03/24/2010): Not vulnerable. This issue did not affect the versions of openssl as shipped with Red Hat Enterprise Linux 3, 4, or 5. Source: https://www.redhat.com/security/data/cve/CVE-2010-0740.html

2010-A-0099: Multiple Vulnerabilities in Apache httpd Resolution: False Positive iDirect servers currently run version 2.2.3-53 of the Apache httpd daemon. Based on the problem description from the Apache Web site this issue was not introduced until version 2.2.9 and only affects Windows, Netware and OS operating systems. Therefore this finding is not applicable to servers supplied by iDirect. Source: http://httpd.apache.org/security/vulnerabilities_22.html

9.2

CAT II Open Findings

2001-T-0017: The OpenSSH UseLogin feature has Multiple Vulnerabilities. Resolution: False Positive Vulnerable Systems: • OpenSSH versions prior to 2.1.1 The version of openssh we provide is greater than or equal to 4.3p2-41.el5.

2003-T-0020: OpenSSH buffer mismanagement and multiple portable OpenSSH PAM vulnerabilities Resolution: False Positive Vulnerable Systems: • OpenSSH versions prior to 3.7.1

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STIG User Guide

Explanation of Specific Open Findings

The version of openssh we provide is greater than or equal to 4.3p2-41.el5.

GEN001020: The root account is logged onto directly. Resolution: false positive This may show up as an open finding if the root account was logged onto directly before the idirect_stig package was installed. The government-provided SRR script checks for unauthorized log ons using the last command. This views historical data and doesn't reflect the machines current state. To eliminate the false positive finding, you can empty the file /var/log/wtmp file as follows: cp /var/log/wtmp /var/log/wtmp.bak cat /dev/null > /var/log/wtmp

WARNING! This will reset the output of the last command. GEN001060: Successful and unsuccessful accesses to the root account are not logged. Resolution: False Positive This may show up as an open finding if no user ever executed the su - command. To eliminate the false positive finding, you can do the following: 1. Log on as a user other than the root user. 2. Execute the following command to log on to the root account: su -

2008-A-0011: SQL Injection in Cisco Unified Communications Manager Resolution: False Positive The Cisco Unified Communications Manager is not installed on iDirect server platforms. The SRR script that generates this finding merely checks that the Operating System being run is Linux. If so, it generates this open finding and marks it for manual review.

STIG User Guide

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Open Findings Fixed by the STIG Scripts

10. Open Findings Fixed by the STIG Scripts Table 2 contains a list of the UNIX STIG recommendations addressed by the iDirect scripts. When the scripts are executed on an iDirect server, the server is modified to comply with the recommendations described in these tables. Table 2. Open Findings Fixed by iDirect Scripts PDI

10

Description

GEN000020

The UNIX host is bootable in single user mode without a password.

GEN000040

The UNIX host is not configured to require a password when booted to single-user mode and is not documented.

GEN000060

The UNIX host cannot be configured to require a password when booted to singleuser mode and is not located in a controlled access area.

GEN000460

After three consecutive unsuccessful login attempts the account is not disabled.

GEN000480

The login delay between login prompts after a failed login is set to less than four seconds.

GEN000540

Passwords can be changed more than once every 24 hours.

GEN000580

A password does not contain a minimum of 14 characters.

GEN000600

A password does not contain at least one upper case and one lower case character.

GEN000620

A password does not contain at least one numeric character.

GEN000640

A password does not contain at least one special character.

GEN000700

Passwords are not changed at least every 60 days.

GEN000800

Passwords are reused within the last five changes.

GEN000820

Global password configuration files are not configured per guidelines.

GEN000980

The root account can be directly logged into from other than the system console.

GEN001260

System log file permissions are more permissive than 640.

GEN001280

Manual page file permissions are more permissive than 644.

GEN001880

Local initialization files are more permissive than 740.

GEN002560

The system and user default umask is not 077.

GEN002680

System audit logs are readable by unauthorized users.

GEN002700

System audit logs are more permissive than 640.

GEN002720

The audit system is not configured to audit failed attempts to access files and programs.

GEN002740

The audit system is not configured to audit files and programs deleted by the user.

GEN002760

The audit system is not configured to audit all administrative, privileged, and security actions.

GEN002960

Access to the cron utility is not controlled via the cron.allow and/or cron.deny files.

GEN003080

Crontab files are more permissive than 600 (700 on some linux systems).

GEN003320

Default accounts are listed in the at.allow file.

STIG User Guide

Open Findings Fixed by the STIG Scripts

Table 2. Open Findings Fixed by iDirect Scripts (continued) PDI

Description

GEN003600

Network parameters are not securely set.

GEN004000

The traceroute command is more permissive than 700.

GEN004540

The sendmail help command is not disabled.

GEN004560

The O Smtp greeting in sendmail.cf, or equivalent, has not been changed to mask the version.

GEN004640

The sendmail decode command is not disabled.

GEN005320

The snmpd.conf file is more permissive than 700.

GEN005360

The snmpd.conf file is not owned by root and group owned by sys or the application.

GEN005400

The /etc/syslog.conf is not owned by root or is more permissive than 640.

GEN005540

Encrypted communications are not configured for IP filtering and logon warning banners.

GEN006620

The access control program is not configured to grant and deny system access to specific hosts.

LNX00320

Special privilege accounts, such as shutdown and halt have not been deleted.

LNX00440

The /etc/login.access or /etc/security/access.conf file is more permissive than 640.

LNX00520

The /etc/sysctl.conf file is more permissive than 600.

STIG User Guide

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