HAProxy must provide default error files.

From VMW vRealize Automation 7.x HA Proxy Security Technical Implementation Guide

Associated with: CCI-001312

SV-99827r1_rule HAProxy must provide default error files.

Vulnerability discussion

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.

Check content

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

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

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.