$_SERVER['SERVER_NAME'] returns someone-else-domain.com

Question

Problem: php script returns someone-else-domain.com in $_SERVER['SERVER_NAME'], but it should return foo.example.com. i don't have that vhost configured nor is it my dyndns/domain. don't know how to find the cause of this.

Current State:

my php script saves the value of $_SERVER['SERVER_NAME'] on each request. i use SERVER_NAME instead of HTTP_HOST because, if i understood the PHP Manual correctly, it's exactly what i need:

SERVER_NAME: "The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host."

the apache2 server is on a debian7 box. i use the dynamic dns service from freedns.afraid.org to point to the server ip. below, foo.example.com is of course not my real dyndns for the server. i got 3 dyndns pointing to my server ip: foo-, bar- and baz.example.com. below is the config for foo. bar and baz are exactly the same except for the domain and paths of course.

the part where SERVER_NAME gets saved. nothing wrong with this i assume:

$this->v['host'] = NULL;
if (isset($_SERVER['SERVER_NAME'])) { 
    $this->v['host'] = str_replace('www.', '', $_SERVER['SERVER_NAME']);
}

/etc/apache2/sites-enabled/foo.example.com

<VirtualHost *:80>
    ServerAdmin webmaster@foo.example.com
    ServerName foo.example.com
    ServerAlias foo # to access from local network, less typing, more time to be lazy
    ServerSignature Off

    DocumentRoot /var/www/foo.example.com/public

    <Directory />
            Options -Indexes +FollowSymLinks
            AllowOverride none
    </Directory>

    <Directory /var/www/foo.example.com/public>
            Options -Indexes +FollowSymLinks +MultiViews
            AllowOverride Options=Indexes
            Order allow,deny
            allow from all
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log
    LogLevel warn
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

/etc/apache2/ports.conf

NameVirtualHost *:80
Listen 80

cat access.log | grep someone-else-domain.com

1.2.3.4 - - [14/Dec/2014:20:11:41 +0100] "GET http://www.someone-else-domain.com/ HTTP/1.1" 200 1488 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0"
1.2.3.5 - - [16/Dec/2014:00:16:14 +0100] "GET http://www.someone-else-domain.com/ HTTP/1.1" 200 1488 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0"
1.2.3.6 - - [18/Dec/2014:01:48:19 +0100] "GET http://www.someone-else-domain.com/ HTTP/1.1" 200 2033 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0"
1.2.3.7 - - [18/Dec/2014:12:18:05 +0100] "GET http://www.someone-else-domain.com/ HTTP/1.1" 200 2153 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0"
1.2.3.8 - - [20/Dec/2014:00:24:23 +0100] "GET http://www.someone-else-domain.com/ HTTP/1.1" 200 2398 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0"

someone has an idea what could have caused this? i could work around this by adding a hosts-whitelist to my script or splitting up PHP_SELF. but first i want to know if i should worry ;)

score 0 · Accepted Answer · edited May 23 '17 at 12:05

while writing and researching i found out that i can fix this problem. and because i wrote so much already, i post the question anyway, hoping someone else is finding it helpful.

Apache2 Directive UseCanonicalName On|Off|DNS:

configures how the server determines its own name and port.

http://httpd.apache.org/docs/2.2/mod/core.html#usecanonicalname

so, if i understood the manual correctly, adding UseCanonicalName On to the virtual host configurations and all should work as expected.

also see this SO Answer: https://stackoverflow.com/a/2297421/668598

$_SERVER['SERVER_NAME'] returns someone-else-domain.com

1 Answers1