SCG WS Apache

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Summary
The Apache HTTP Server Project is a collaborative software development effort aimed at creating a robust, commercial-grade, featureful, and freely-available source code implementation of an HTTP (Web) server. The project is jointly managed by a group of volunteers located around the world, using the Internet and the Web to communicate, plan, and develop the server and its related documentation. This project is part of the Apache Software Foundation. In addition, hundreds of users have contributed ideas, code, and documentation to the project. This file is intended to briefly describe the history of the Apache HTTP Server and recognize the many contributors.

Apache Global Server Configuration Files
Debian /etc/apache2/apache2.conf RHEL / Red Hat / CentOS / Fedora Linux /etc/httpd/conf/httpd.conf FreeBSD /usr/local/etc/apache2X/httpd.conf

Note:X represents the version number

Apache Module Files
Debian /etc/apache2/mods-enabled RHEL / Red Hat / CentOS / Fedora Linux /etc/httpd/conf/conf.d

Apache Port Configuration File
Debian /etc/apache2/ports.conf RHEL / Red Hat / CentOS / Fedora Linux /etc/httpd/conf/conf.d

Apache Error Files
Debian /var/log/apache2/error.log RHEL / Red Hat / CentOS / Fedora Linux var/log/httpd/error_log FreeBSD /var/log/httpd-error.log

Description
This Directive Controls wheather Server response field is sent back to clients includes a description of Generic OS Type of the Server.

Server: Apache/2.2.14 (Unix) mod_ssl/2.2.14 OpenSSL/0.9.8e-fips-rhel5

This allows attackers to identify web servers details greatly and increases the efficiency of any attack,as security vulnerabilities are dependent upon specific software versions.

How to test
In order to test for ServerToken configuration, one should check the Apache configuration file.

Misconfiguration
ServerTokens Full

Remediation
Configure the ServerTokens directive in the Apache configuration to value of Prod or ProductOnly. This tells Apache to only return "Apache" in the Server header, returned on every page request.

ServerTokens Prod or ServerTokens ProductOnly

Description
This Apache directive allows the configuration of a trailing footer line under server-generated documents.

How to test
In order to test for ServerSignature configuration, one should check the Apache configuration file.

Misconfiguration
ServerSignature On

Remediation
Configure the ServerSingature directive in the Apache configuration to value of "Off". This tell Apache not to display the server version on error pages, or other pages it generates.

ServerSignature On

Description
Apache typically is started with root privileges in order to listen on port 80 and 443. One of the best ways to reduce your exposure to attack when running a web server is to create a unique, unprivileged userid and group for the web daemon to execute. The “nobody” or “daemon” userid & group that come default on Unix variants should NOT be used to run the web server as these principals are commonly used by other daemon services. Instead, create a user and group that are exclusively used by the web service so as to not give unnecessary access to other services. The userid used for the apache user should be a unique value between 1 and 499 as these lower values are reserved for the special system accounts. A more secure alternative is to bind Apache web service to an unprivileged port so it is not necessary to start Apache as root.

How to test
Ensure the apache account is unique and has been created with a UID between1-499 with the apache group and configured in the Apache Configuration File.

Remediation
If the Apache user and group does exist, create the account and group as a unique system account.

Example:
 * 1) groupadd –r apache
 * 2) useradd apache -r -g apache -d /var/www -s /sbin/nologin

2. Configure the Apache user and group in the Apache configuration file. User apache Group apache

Description
The Apache account must not be used as a regular login account, and should be assigned an invalid or nologin shell to ensure that the account cannot be used to login.

Misconfiguration
Check the apache login shell in the /etc/password file for Linux Systems.
 * 1) grep apache /etc/passwd

Remediation
The below command will configure the apache user with "nologin" restrictions. Expected Output Command to chec: Expected Output: apache:x:48:48:Apache:/var/www:usr/sbin/nologin
 * 1) chsh -s /usr/sbin/nologin apache
 * 1) cat/etc/passwd

Description
The user account under which Apache runs, should have a valid password, but should be locked.

Misconfiguration
The below is the misconfiguration for an Apache user.

Command


 * 1) passwd -S apache

Expected Output:

apache P 09/07/2015 0 99999 7 -1

Remediation

 * 1) passwd -l apache

Validate the Configuration using the below command in Linux.


 * 1) passwd -S apache

Expected Output:

apache LK 2015-09-09 0 99999 7 -1

Description
All of the Apache Software directories and files installed should be owned by root user and root group.This will help in mitigate exploration severity and information disclosure.

Apache Web Document folders like "/var/www/html" need a designated group to allow web content to be updated.

How to test
Type the below command to check the User and Group associated with a file.The file varies in Between Debian,RHEL/CentOS/Fedora,FreeBSD.

Example:


 * 1) ls -l /usr/share/apache2

Misconfiguration
In the Below example the apache2 folder is owned by a user name "alice" and group "sysadmin" which can be considered as a misconfiguration.

drwxr-xr-x   6 alice sysadmin 4096 Sep  7 13:20 apache2

Remediation
The below command will set a Directory named "apache2" with root user and root group recursively.


 * 1) chown –R root:root /usr/local/apache2

Description
Setting the appropriate permissions on the Apache files and directories can help to prevent/mitigate exploitation severity and information disclosure.

Preventing execution of Apache binaries with limited permission will decrease the attack surface.

Permission of the Apache directories and files should be rwxr-xr-x and they can change if it is Apache binary or executable file.

How to test
Run the below command to check the file permissions.


 * 1) ls -l /var/www/html

Misconfiguration
Other than rwxr-xr-x would be considered as a mis configuration.

Remediation
Permission of the Apache directories and files should be rwxr-xr-x and they can change if it is Apache binary or executable file.

Description
Apache will serve any file mapped from an URL to clients with efault configuration.

It is better to create a deny policy that will not allow access to Operating system directoories or files.

A small modification in the configuration will allow access to tthe required files.

The order of the directive is important as it provides for otherr Allow diectives to override the default deny.

How to test
1. Find the appropriate Apache configuration file in your Server. 2. Ensure there is a single Order directive and set the value to deny, allow 3. Ensure there is a Deny directive, and set the value to "from all". 4. Remove any Allow directives from the root  element.

Misconfiguration
 . . . Order allow,deny Allow from all . . . 

Remediation
 . . . Order deny,allow Deny from all . . . 

Description
Appropriate access to various files,directories, locations and virtual hosts that contains web site content can make attack surface strong.

Based up on the requirement you can provide allow access or you can deny.

How to test
1. Find the appropriate Apache configuration file in your Server. 2. Ensure there is a single Order directive and set the value to deny, allow 3. Ensure there is a Deny directive, and set the value to "from all". 4. Remove any Allow directives from the root  element.

MisConfiguration
 . . . Order deny,allow Allow from all 

Remediation
 Order deny,allow deny from all allow from 172.16.5.0/24 

Misconfiguration
 AllowOverride All 

Remediation
 AllowOverride None 

Description
Apache Server is capable of accepting and processing GET,HEAD,POST,OPTIONS,PUT,DELETE HTTP request methods. If we use  directive then Apache will not process the unnecessary HTTP request methods. The primary security concerened is to disable the unnecessary HTTP request methods. Apache  directive does not deny the TRACE request method.

Misconfiguration
By default all the HTTP request methods are accepted by Apache Server.

Remediation
 . . .	<LimitExcept GET POST OPTIONS> deny from all </LimitExcept> </Directory>
 * 1) Limit HTTP methods

Description
HTTP Trace Method is enabled by default on the Apache Web Server. This method intended for diagnostics purposes.

How to test
Method 1: 1. Locate the Apache configuration files and included configuration files. 2. Verify there is a single TraceEnable directive configured with a value of off.

Method 2: Telnet on the port your web server is running and request for “TRACE / HTTP/1.0” if you get a positive reply it means TRACE is enabled on your system. The output of a server with TRACE enabled will look like:

Misconfiguration
Below is an example of MisConfiguration. TraceEnable on

Remediation
1.Locate the main Apache configuration file such as httpd.conf. 2.Add a TraceEnable directive to the server level configuration with a value of off as shown TraceEnable off

Description
Many attacks in the process of enumeration they use Vulnerability Scanners,Automated Programs and other fingerprinting tools to send abnormal HTTP protocol version to check how Web Server responds and it is very important that we need to deny these requests.

How to test
1.Locate the Apache configuration files and included configuration files. 2.Verify that below module is loaded. mod_rewrite.so

Misconfiguration
By default this module is not loaded.So we need to load the module.

Remediation
Method1: While compiling the Apache for installation we can enable this module and then install it. If the Apache is installed with default parameter then we can also use the below Method Method2: 1.Locate the Apache configuration files and included configuration files. 2.Add the following line to the Configuration file. LoadModule rewrite_module modules/mod_rewrite.so 3.Add/change the RewriteEngine directive to the configuration as shown. RewriteEngine On RewriteCond %{THE_REQUEST} !HTTP/1\.1$ RewriteRule .* - [F]
 * 1) ./configure --enable-rewrite

Description
The following configuration prevent .htaccess and .htpasswd files from being viewed by Web clients.

How to test
Verify the below recommended configuration is present in the Apache config file and make sure they are not commented out.

Misconfiguration
Below is the Misconfiguration <FilesMatch "^\.ht"> Order allow </FilesMatch>

Remediation
1.Locate the Apache configuration files and included configuration files. 2.Add the following line to the Configuration file. <FilesMatch "^\.ht"> Order allow,deny Deny from all Satisfy All </FilesMatch>

Description
There are many files that are often left within the web server document root that could provide an attacker with sensitive information. Most often these files are mistakenly left behind after installation, trouble-shooting, or backing up files before editing. We use FilesMatch directive to restrict access to only those file extensions that are appropriate for the web server.

How to test
Verify the below recommended configuration is present in the Apache config file and make sure they are not commented out.

Misconfiguration
Block all files by default, unless specifically allowed. <FilesMatch "^.*$"> Order Deny,Allow Deny from all </FilesMatch>

Remediation
1.Locate the Apache configuration files and included configuration files. 2.Add the following line to the Configuration file so that Web Server Allow files with specifically approved file extensions such as "css,htm,html,js,pdf,txt,xml,xsl" <FilesMatch "^.*\.(css|html?|js|pdf|txt|xml|xsl|gif|ico|jpe?g|png)$"> Order Deny,Allow Allow from all </FilesMatch>

Note: File extensions should be matched carefully and should be changed based upon the reqruiement.

Description
All of the Web Servers comes with a default page which is not required.

How to test
Review all pre-installed web pages and remove content which is not required from root directory of the Web Server.

Misconfiguration
Post installation of the Web Server if the below items exits in Server then that is considered as a Misconfiguration. 1.Default Index Pages 2.Welcome Page 3.Apache User Manul 4.Server Information Handlers and Status Handlers.

Remediation
1.Remove the default index pages like ( index.html,default.html) 2.Remove the Welcome pages. 3.Remove the Apache User manuals. 4.Remove any Server Information Handlers and Status Handlers with configuration.