HAProxy must provide default error files.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-240070	VRAU-HA-000315	SV-240070r879655_rule		Medium

Description
Information needed by an attacker to begin looking for possible vulnerabilities in a web server includes any information about the web server, backend systems being accessed, and plug-ins or modules being used. Web servers will often display error messages to client users displaying enough information to aid in the debugging of the error. The information given back in error messages may display the web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage. This information could be used by an attacker to blueprint what type of attacks might be successful. The information given to users must be minimized to not aid in the blueprinting of the web server.

Description

Information needed by an attacker to begin looking for possible vulnerabilities in a web server includes any information about the web server, backend systems being accessed, and plug-ins or modules being used. Web servers will often display error messages to client users displaying enough information to aid in the debugging of the error. The information given back in error messages may display the web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage. This information could be used by an attacker to blueprint what type of attacks might be successful. The information given to users must be minimized to not aid in the blueprinting of the web server.

STIG	Date
VMW vRealize Automation 7.x HA Proxy Security Technical Implementation Guide	2023-09-12

Details

Check Text ( C-43303r665377_chk )
At the command prompt, execute the following command: grep 'errorfile' /etc/haproxy/haproxy.cfg If the return value for "errorfile" does not list error pages for the following HTTP status codes, this is a finding. 400, 403, 408, 500, 502, 503, 504

Fix Text (F-43262r665378_fix)
Create error pages for each of the HTTP status codes below: 400, 403, 408, 500, 502, 503, 504 Navigate to and open /etc/haproxy/haproxy.cfg. Navigate to the "defaults" section. Add the following lines: errorfile 400 /path/to/errorPage/for/400.http errorfile 403 /path/to/errorPage/for/403.http errorfile 408 /path/to/errorPage/for/408.http errorfile 500 /path/to/errorPage/for/500.http errorfile 502 /path/to/errorPage/for/502.http errorfile 503 /path/to/errorPage/for/503.http errorfile 504 /path/to/errorPage/for/504.http

Fix Text (F-43262r665378_fix)

Create error pages for each of the HTTP status codes below:

400, 403, 408, 500, 502, 503, 504

Navigate to and open /etc/haproxy/haproxy.cfg. Navigate to the "defaults" section.

Add the following lines:

errorfile 400 /path/to/errorPage/for/400.http
errorfile 403 /path/to/errorPage/for/403.http
errorfile 408 /path/to/errorPage/for/408.http
errorfile 500 /path/to/errorPage/for/500.http
errorfile 502 /path/to/errorPage/for/502.http
errorfile 503 /path/to/errorPage/for/503.http
errorfile 504 /path/to/errorPage/for/504.http