Knowledge Base

Roundcube/Horde webmail and websites on FastCGI are not accessible: Connection reset by peer: mod_fcgid: error reading data from FastCGI server

Symptoms

Webmail:
- Roundcube/Horde webmail shows the following error message in a web browser:
  
  Service Temporarily Unavailable
  The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
  Apache Server at webmail.example.com Port 80
  
  500 external Server Error
- The following messages appear in /var/log/psa-horde/psa-horde.log or /var/log/apache2/error.log:
  
  [warn] [client 203.0.113.2] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server
  [error] [client 203.0.113.2] Premature end of script headers: index.php
- The following error messages may appear in /var/log/httpd/suexec_log:
  
  uid: (10021/horde_sysuser) gid: (510/510) cmd: cgi_wrapper
  target uid/gid (10021/510 or 504) mismatch with directory (0/503) or program (0/0)
  uid: (2523/horde_sysuser) gid: (2521/2521) cmd: cgi_wrapper
  directory is writable by others: (/var/www/cgi-bin/cgi_wrapper)
  
  uid: (996/roundcube_sysuser) gid: (1006/1006) cmd: cgi_wrapper
  file has no execute permission: (/var/www/cgi-bin/cgi_wrapper/cgi_wrapper)
Websites on FastCGI:
- Websites served by the PHP FastCGI handler are not loading with a 500 error. After changing a PHP handler to PHP-FPM, websites start to work.
- CGI scripts do not work on a website.
- Following error messages in /var/www/vhosts/system/example.com/logs/error_log:
  [warn] [client 203.0.113.2] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server
  [error] [client 203.0.113.2] Premature end of script headers: index.php
Plesk migration:
- The following warning appears during a Plesk migration:
  
  WARNING:()The webmail service horde is unavailable. It will be replaced with <webmail> for the following objects: <list of domains>

Cause

Permissions on the file /var/www/cgi-bin/cgi_wrapper are incorrect.

Resolution

Connect to the server via SSH
Correct the permissions:

# chown root:root /var/www
# chmod 0755 /var/www
# chown -R root:root /var/www/cgi-bin
# chmod 0755 /var/www/cgi-bin
# chmod -R 0755 /var/www/cgi-bin/cgi_wrapper