Check: AS24-U2-000870
Apache Server 2.4 UNIX Site STIG:
AS24-U2-000870
(in versions v2 r4 through v2 r3)
Title
The Apache web server cookies, such as session cookies, sent to the client using SSL/TLS must not be compressed. (Cat II impact)
Discussion
A cookie is used when a web server needs to share data with the client's browser. The data is often used to remember the client when the client returns to the hosted application at a later date. A session cookie is a special type of cookie used to remember the client during the session. The cookie will contain the session identifier (ID) and may contain authentication data to the hosted application. To protect this data from easily being compromised, the cookie can be encrypted. When a cookie is sent encrypted via SSL/TLS, an attacker must spend a great deal of time and resources to decrypt the cookie. If, along with encryption, the cookie is compressed, the attacker can now use a combination of plaintext injection and inadvertent information leakage through data compression to reduce the time needed to decrypt the cookie. This attack is called Compression Ratio Info-leak Made Easy (CRIME). Cookies shared between the Apache web server and the client when encrypted should not also be compressed.
Check Content
In a command line, run "httpd -M | grep -i ssl_module". If "ssl_module" is not listed, this is a finding. 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. If the "SSLCompression" directive does not exist or is set to "on", this is a finding.
Fix Text
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" Ensure the "SSLCompression" is added and looks like the following: SSLCompression off Restart Apache: apachectl restart
Additional Identifiers
Rule ID: SV-214301r881516_rule
Vulnerability ID: V-214301
Group Title: SRG-APP-000439-WSR-000153
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-002448 |
The organization distributes asymmetric cryptographic keys using: NSA-approved key management technology and processes; approved PKI Class 3 certificates or prepositioned keying material; or approved PKI Class 3 or Class 4 certificates and hardware security tokens that protect the user^s private key. |
Controls
Number | Title |
---|---|
SC-12 (3) |
Asymmetric Keys |