The Apache web server must generate unique session identifiers that cannot be reliably reproduced.

From Apache Server 2.4 UNIX Server Security Technical Implementation Guide

Associated with: CCI-001188

AS24-U1-000500_rule The Apache web server must generate unique session identifiers that cannot be reliably reproduced.

Vulnerability discussion

Communication between a client and the Apache web server is done using the HTTP protocol, but HTTP is a stateless protocol. To maintain a connection or session, a web server will generate a session identifier (ID) for each client session when the session is initiated. The session ID allows the Apache web server to track a user session and, in many cases, the user, if the user previously logged into a hosted application.Unique session IDs are the opposite of sequentially generated session IDs, which can be easily guessed by an attacker. Unique session identifiers help to reduce predictability of generated identifiers. Unique session IDs address man-in-the-middle attacks, including session hijacking or insertion of false information into a session. If the attacker is unable to identify or guess the session information related to pending application traffic, the attacker will have more difficulty in hijacking the session or otherwise manipulating valid sessions.

Check content

Determine the location of the "HTTPD_ROOT" directory and the "httpd.conf" file: # httpd -V | egrep -i 'httpd_root|server_config_file' -D HTTPD_ROOT="/etc/httpd" -D SERVER_CONFIG_FILE="conf/httpd.conf" Verify the "mod_unique_id" is loaded. If it does not exist, this is a finding.

Fix text

Determine the location of the "HTTPD_ROOT" directory and the "httpd.conf" file: # httpd -V | egrep -i 'httpd_root|server_config_file' -D HTTPD_ROOT="/etc/httpd" -D SERVER_CONFIG_FILE="conf/httpd.conf" Load the "mod_unique_id" module. Restart Apache: apachectl restart

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