The remote Debian host is missing a security-related update.
Hanno Boeck discovered that incorrect parsing of Limit directives of .htaccess files by the Apache HTTP Server could result in memory disclosure.
Upgrade the apache2 packages. For the oldstable distribution (jessie), this problem has been fixed in version 2.4.10-10+deb8u11. For the stable distribution (stretch), this problem has been fixed in version 2.4.25-3+deb9u3.