Use prepared statements. These are SQL statements that sent to and parsed by the database server separately from any parameters.
If you use PDO you can work with prepared statements like this:$preparedStatement = $db->prepare('SELECT * FROM employees WHERE name = :name');$preparedStatement->execute(array(':name' => $name));$rows = $preparedStatement->fetchAll();
$dbis a PDO object, see the PDO documentation)
What happens is that the SQL statement you pass to
prepareis parsed and compiled by the database server. By specifying parameters (either a
?or a named parameter like
:namein the example above) you tell the database engine where you want to filter on. Then when you call
executethe prepared statement is combined with the parameter values you specify.
The important thing here is that the parameter values are combined with the compiled statement, not a SQL string. SQL injection works by tricking the script into including malicious strings when it creates SQL to send to the database. So by sending the actual SQL separately from the parameters you limit the risk of ending up with something you didn’t intend. Any parameters you send when using a prepared statement will just be treated as strings (although the database engine may do some optimization so parameters may end up as numbers too, of course). In the example above, if the
'Sarah'; DELETE * FROM employeesthe result would simply be a search for the string “‘Sarah’; DELETE * FROM employees”, and you will not end up with an empty table.
Another benefit with using prepared statements is that if you execute the same statement many times in the same session it will only be parsed and compiled once, giving you some speed gains.
Oh, and since you asked about how to do it for an insert, here’s an example:$preparedStatement = $db->prepare('INSERT INTO table (column) VALUES (:column)');$preparedStatement->execute(array(':column' => $unsafeValue));
Backup your fstab file
cp /etc/fstab /etc/fstab.bak
Creating tmpmnt partition file (Around 1Gb in size)
cd /vardd if=/dev/zero of=tmpMnt bs=1024 count=1048576
Format the new partition
mkfs.ext3 -j /var/tmpMnt
Press Y when asked
Making backup of old /tmp
cp -Rp /tmp /tmp_backup
Mount the tmp filesystem
mount -o loop,noexec,nosuid,rw /var/tmpMnt /tmp
Set the right permissions
chmod 0777 /tmp
Copy the files back to new tmp folder
cp -Rp /tmp_backup/* /tmp/
Adding new /tmp filesystem to fstab
echo "/var/tmpMnt /tmp ext3 loop,rw,noexec,nosuid,nodev 0 0" >> /etc/fstab
No need for 2 tmp filesystems, so we symlink /var/tmp to /tmp
rm -rf /var/tmp/ln -s /tmp/ /var/tmp