1. Prevent jumping out of the web directory
First modify httpd.conf. If you only allow your php script program to operate in the web directory, you can also modify the httpd.conf file to limit the operation path of php. For example, if your web directory is /usr/local/apache/htdocs, then add these lines to httpd.conf:
php_admin_value open_basedir /usr/local/apache
/htdocs
In this way, if the script wants to read files other than /usr/local/apache/htdocs, it will not be allowed. If the error display is turned on, an error like this will be prompted:
Warning: open_basedir restriction in effect. File is in wrong directory in
/usr/local/apache/htdocs/open.php on line 4
Wait.
2. Prevent php Trojan from executing webshell
Turn on safe_mode,
Setting
in php.iniDisable_functions= passthru, exec, shell_exec, system
You can choose one of the two, or you can choose both
3. Prevent php Trojan from reading and writing file directories
in php.ini
Disable_functions= passthru, exec, shell_exec, system
Add php file processing function at the end
Mainly include
fopen, mkdir, rmdir, chmod, unlink, dir
fopen, fread, fclose, fwrite, file_exists
closedir, is_dir, readdir.opendir
fileperms.copy, unlink, delfile
It becomes
Disable_functions= passthru, exec, shell_exec, system, fopen, mkdir, rmdir, chmod, unlink, dir
, fopen, fread, fclose, fwrite, file_exists
, closedir, is_dir, readdir.opendir
, fileperms.copy, unlink, delfile
OK, we’re done, the PHP Trojan can’t defeat us. Unfortunately, in this case, things that use text databases won’t work.
If the apache is built on the windos platform, we need to pay attention to one thing. By default, apache runs with system permissions, which is scary and makes people feel uncomfortable. Then we should lower the permissions of apache.
net user apache fuckmicrosoft /add
net localgroup users apache /del
OK. We have created a user apche that does not belong to any group.
We open the computer manager, select services, click on the properties of the apache service, we select log on, select this account, we fill in the account and password created above, restart the apache service, ok, apache runs under low privileges .
In fact, we can also set the permissions of each folder so that the apache user can only perform what we want it to do, and create a separate read-write user for each directory. This is also a popular configuration method used by many virtual host providers. However, this method is overkill when used to prevent this.