The Apache web server must generate a session ID using as much of the character set as possible to reduce the risk of brute force.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-214253	SRG-APP-000224-WSR-000138	AS24-U1-000520	SV-214253r1043181_rule	2024-12-04	3

Description
Generating a session identifier (ID) that is not easily guessed through brute force is essential to deter several types of session attacks. By knowing the session ID, an attacker can hijack a user session that has already been user-authenticated by the hosted application. The attacker does not need to guess user identifiers and passwords or have a secure token since the user session has already been authenticated. By generating session IDs that contain as much of the character set as possible, i.e., A-Z, a-z, and 0-9, the session ID becomes exponentially harder to guess. Satisfies: SRG-APP-000223-WSR-000145, SRG-APP-000224-WSR-000135, SRG-APP-000224-WSR-000136, SRG-APP-000224-WSR-000138

Description

Generating a session identifier (ID) that is not easily guessed through brute force is essential to deter several types of session attacks. By knowing the session ID, an attacker can hijack a user session that has already been user-authenticated by the hosted application. The attacker does not need to guess user identifiers and passwords or have a secure token since the user session has already been authenticated. By generating session IDs that contain as much of the character set as possible, i.e., A-Z, a-z, and 0-9, the session ID becomes exponentially harder to guess. Satisfies: SRG-APP-000223-WSR-000145, SRG-APP-000224-WSR-000135, SRG-APP-000224-WSR-000136, SRG-APP-000224-WSR-000138

ℹ️ Check
Determine the location of the "HTTPD_ROOT" directory and the "httpd.conf" file: # apachectl -V \| egrep -i 'httpd_root\|server_config_file' -D HTTPD_ROOT="/etc/httpd" -D SERVER_CONFIG_FILE="conf/httpd.conf" Note: The apachectl front end is the preferred method for locating the Apache httpd file. For some Linux distributions, "apache2ctl -V" or "httpd -V" can also be used. Verify the "unique_id_module" is loaded: run httpd -M \| grep unique_id If no unique_id is returned, this is a finding.

ℹ️ Check

Determine the location of the "HTTPD_ROOT" directory and the "httpd.conf" file: # apachectl -V | egrep -i 'httpd_root|server_config_file' -D HTTPD_ROOT="/etc/httpd" -D SERVER_CONFIG_FILE="conf/httpd.conf" Note: The apachectl front end is the preferred method for locating the Apache httpd file. For some Linux distributions, "apache2ctl -V" or "httpd -V" can also be used. Verify the "unique_id_module" is loaded: run httpd -M | grep unique_id If no unique_id is returned, this is a finding.

✔️ Fix
Determine the location of the "HTTPD_ROOT" directory and the "httpd.conf" file: # apachectl -V \| egrep -i 'httpd_root\|server_config_file' -D HTTPD_ROOT="/etc/httpd" -D SERVER_CONFIG_FILE="conf/httpd.conf" Load the "unique_id_module". Example: LoadModule unique_id_module modules/mod_unique_id.so Restart Apache: apachectl restart