What follows is my httpd.conf file on High-Sierra. It initially failed for cgi-bin scripts involving Perl (.pl). However, I missed UN-commenting a couple of critical lines. I didn't think I needed 'cgi_mod', but I do. Thanks to 'etrasoft' from the Apple Community, I was able to remedy that, and now my cgi-bin scripts EXECUTE properly. ALL of my settings are shown below. Substitute YOURNAME as appropriate. I also recommend your CGI directory have the following settings: ('sudo' gives you admin access)
sudo chmod 775 /Library/WebServer/CGI-Executables
sudo chown root:admin /Library/WebServer/CGI-Executables
Also, if you have a 'yourname' sub-directory within the CGI directory, you'll want to do similar changes using 'yourname' in place of 'root' to your sub-directory.
There are two primary reasons:
1) You need write access to put CGI and Perl scripts there,
2) You don't want non-administrators to have access, which prevents malware.
======================================
ServerRoot "/usr"
<IfDefine SERVER_APP_HAS_DEFAULT_PORTS>
Listen 8080
</IfDefine>
<IfDefine !SERVER_APP_HAS_DEFAULT_PORTS>
Listen 80
</IfDefine>
LoadModule authn_file_module libexec/apache2/mod_authn_file.so
LoadModule authn_core_module libexec/apache2/mod_authn_core.so
LoadModule authz_host_module libexec/apache2/mod_authz_host.so
LoadModule authz_groupfile_module libexec/apache2/mod_authz_groupfile.so
LoadModule authz_user_module libexec/apache2/mod_authz_user.so
LoadModule authz_core_module libexec/apache2/mod_authz_core.so
LoadModule access_compat_module libexec/apache2/mod_access_compat.so
LoadModule auth_basic_module libexec/apache2/mod_auth_basic.so
LoadModule reqtimeout_module libexec/apache2/mod_reqtimeout.so
LoadModule filter_module libexec/apache2/mod_filter.so
LoadModule mime_module libexec/apache2/mod_mime.so
LoadModule log_config_module libexec/apache2/mod_log_config.so
LoadModule env_module libexec/apache2/mod_env.so
LoadModule headers_module libexec/apache2/mod_headers.so
LoadModule setenvif_module libexec/apache2/mod_setenvif.so
LoadModule version_module libexec/apache2/mod_version.so
LoadModule slotmem_shm_module libexec/apache2/mod_slotmem_shm.so
LoadModule unixd_module libexec/apache2/mod_unixd.so
LoadModule status_module libexec/apache2/mod_status.so
LoadModule autoindex_module libexec/apache2/mod_autoindex.so
LoadModule cgi_module libexec/apache2/mod_cgi.so
LoadModule negotiation_module libexec/apache2/mod_negotiation.so
LoadModule dir_module libexec/apache2/mod_dir.so
LoadModule userdir_module libexec/apache2/mod_userdir.so
LoadModule alias_module libexec/apache2/mod_alias.so
LoadModule php7_module libexec/apache2/libphp7.so
LoadModule perl_module libexec/apache2/mod_perl.so
LoadModule hfs_apple_module libexec/apache2/mod_hfs_apple.so
<IfModule unixd_module>
User _www
Group _www
</IfModule>
ServerAdmin YOURNAMR@gmail.com
ServerName localhost
<Directory />
AllowOverride none
Require all denied
</Directory>
DocumentRoot "/Users/YOURNAME/Sites"
<Directory "/Users/YOURNAME/Sites">
Options FollowSymLinks Multiviews
MultiviewsMatch Any
AllowOverride All
Require all granted
</Directory>
<IfModule dir_module>
DirectoryIndex index.html
</IfModule>
<FilesMatch "^\.([Hh][Tt]|[Dd][Ss]_[Ss])">
Require all denied
</FilesMatch>
<Files "rsrc">
Require all denied
</Files>
<DirectoryMatch ".*\.\.namedfork">
Require all denied
</DirectoryMatch>
ErrorLog "/private/var/log/apache2/error_log"
LogLevel warn
<IfModule log_config_module>
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %b" common
<IfModule logio_module>
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
</IfModule>
CustomLog "/private/var/log/apache2/access_log" common
</IfModule>
<IfModule alias_module>
ScriptAliasMatch ^/cgi-bin/((?!(?i:webobjects)).*$) "/Library/WebServer/CGI-Executables/$1"
</IfModule>
<Directory "/Library/WebServer/CGI-Executables">
AllowOverride All
Require all granted
Options ExecCGI Includes MultiViews Indexes SymLinksIfOwnerMatch
AddHandler cgi-script .cgi .pl
</Directory>
<IfModule headers_module>
RequestHeader unset Proxy early
</IfModule>
<IfModule mime_module>
TypesConfig /private/etc/apache2/mime.types
AddType application/x-compress .Z
AddType application/x-gzip .gz .tgz
AddType text/html .shtml
AddOutputFilter INCLUDES .shtml
</IfModule>
TraceEnable off
Include /private/etc/apache2/extra/httpd-mpm.conf
Include /private/etc/apache2/extra/httpd-autoindex.conf
Include /private/etc/apache2/extra/httpd-userdir.conf
<IfModule proxy_html_module>
Include /private/etc/apache2/extra/proxy-html.conf
</IfModule>
<IfModule ssl_module>
SSLRandomSeed startup builtin
SSLRandomSeed connect builtin
</IfModule>
Include /private/etc/apache2/other/*.conf