/ 
CGI-Session-4.42 UNAUTHORIZED RELEASE
/ CGI::Session::Driver::mysql
Security Advisories (1)
CVE-2026-56016 (2026-07-01)

CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources. The generate_id method builds the session id from a MD5 digest of the process id, the epoch time, and the built-in rand() function. All three are predictable, low-entropy sources: the PID is drawn from a small range, the epoch time can be guessed or read from the HTTP Date header, and Perl's rand() is unsuitable for security purposes because it is predictable and reversible. An attacker who predicts a session id can impersonate the corresponding session and bypass authentication.

NAME

CGI::Session::Driver::mysql - CGI::Session driver for MySQL database

SYNOPSIS

$s = new CGI::Session( 'driver:mysql', $sid);
$s = new CGI::Session( 'driver:mysql', $sid, { DataSource  => 'dbi:mysql:test',
                                               User        => 'sherzodr',
                                               Password    => 'hello' });
$s = new CGI::Session( 'driver:mysql', $sid, { Handle => $dbh } );

DESCRIPTION

mysql stores session records in a MySQL table. For details see CGI::Session::Driver::DBI, its parent class.

It's especially important for the MySQL driver that the session ID column be defined as a primary key, or at least "unique", like this:

CREATE TABLE sessions (
    id CHAR(32) NOT NULL PRIMARY KEY,
    a_session TEXT NOT NULL
 );

To use different column names, change the 'create table' statement, and then simply do this:

$s = new CGI::Session('driver:mysql', undef,
{
    TableName=>'session',
    IdColName=>'my_id',
    DataColName=>'my_data',
    DataSource=>'dbi:mysql:project',
});

or

$s = new CGI::Session('driver:mysql', undef,
{
    TableName=>'session',
    IdColName=>'my_id',
    DataColName=>'my_data',
    Handle=>$dbh,
});

DRIVER ARGUMENTS

mysql driver supports all the arguments documented in CGI::Session::Driver::DBI. In addition, DataSource argument can optionally leave leading "dbi:mysql:" string out:

$s = new CGI::Session( 'driver:mysql', $sid, {DataSource=>'shopping_cart'});
# is the same as:
$s = new CGI::Session( 'driver:mysql', $sid, {DataSource=>'dbi:mysql:shopping_cart'});

BACKWARDS COMPATIBILITY

As of V 4.30, the global variable $CGI::Session::MySQL::TABLE_NAME cannot be used to set the session table's name.

This is due to changes in CGI::Session::Driver's new() method, which now allows the table's name to be changed (as well as allowing both the 'id' column name and the 'a_session' column name to be changed).

See the documentation for CGI::Session::Driver::DBI for details.

In particular, the new syntax for new() applies to all database drivers, whereas the old - and bad - global variable method only applied to MySQL.

Alternately, call $session -> table_name('new_name') just after creating the session object if you wish to change the session table's name.

LICENSING

For support and licensing see CGI::Session.