MySQL server security

MySQL SecurityWashington DC, USA

November 8th, 2007

Agenda

Why is security important?

Privileges management

Configuration directives

MySQL security on the Web

Next challenge for security

Who is speaking?

Damien Séguy

LAMP expert services at NexenServices.com

'Sécurité PHP 5 et MySQL' with Philippe Gamache at Eyrolles

http://www.nexen.net/

Common fears

Root overtake

Data erasing

Denial of service

Data modification

Data publication

Plain shame....

Default privileges

Root account, no password

Always ADD A password

Renaming root to 'chef'?

Users and test bases

Users without password

Users without IP restrictions

Anonymous users

User table sanity checksAnonymous users

SELECT count(*) FROM users WHERE user='';

Avoid % in addresses

SELECT count(*) FROM users WHERE host LIKE '%\%%';

Alwas have a password

SELECT count(*) FROM users WHERE password='';

The FILE privilege

Export data to file

Import data to file

Import data from the client

The GRANT privilege

Share your privileges

Privilege escalation

Complement by exchanging rights with other users

Configuration directives

--skip-grant-tables

--old-password

--secure-auth

--skip-show-databases

Configuration directives (2)

--port=3306

--skip-networking

--bind-address

--skip-name-resolve

--skip-symbolic-links

Configuration directives (3)

--local-infile=0

--secure-file-priv

--chroot

--open-files-limit

--safe-user-create

--allow-suspicous-udf

Client configuration directives

--secure-auth

--safe-updates

also called : --i-am-a-dummy

--select_limit=1000

--max_join_size

Resource consuming

+-----------------------+------+| Field | Null |+-----------------------+------+| max_questions | NO || max_updates | NO || max_connections | NO || max_user_connections | NO |+-----------------------+------+

In the User table

Max_connections

Max_user_connections

Max_questions

Max_updates

Inactive by default

Valid for an hour

SQL injectionsDynamic build of the SQL query

$requete = "SELECT COUNT(*) FROM users WHERE login='".$_GET['login']."' AND motdepasse='".$_GET['password']."' ";

Mixing data and instructions

It is always possible to escape this quoting, and make the query do other things

Injections patternsWHERE clause removal

WHERE login = '' or 1 or ''

Subqueries

WHERE id=(SELECT BENCHMARK(md5(1),1000));

UNION

WHERE id=1 UNION SELECT * FROM table;

Multiple insertions

VALUES ('login'),('admin');

MySQL special chars

' and " : string delimiters

() : sub queries

% and _ : regex with LIKE

REGEXP

; \g \G : end of command

--, # et /* .... */ comment

Protecting against injectionsProtecting special characters

with PHP : use mysqli_real_escape_string() AND delimiters

$sql = "SELECT * FROM table WHERE id = '".mysqli_real_escape_string($mid, $_GET['id'])."'";

The case of integers : force the type before building the query

ProtectionsPrepared queries

Prepare the command execution

Affect variables

Execute the command

/* Preparing command execution */$query = "INSERT INTO cities (Name, Country, Region) VALUES (?,?,?)";$stmt = $mysqli->prepare($query);

$val1 = 'Washington';$val2 = 'USA';$val3 = 'DC';

$stmt->bind_param("sss", $val1, $val2, $val3);

/* Commande execution */$stmt->execute();

$val1 = 'Montréal';$val2 = 'CAN';$val3 = 'Québec';

/* Commande execution */$stmt->execute();

/* Free resources */$stmt->close();

Other protectionsStored procedures

MySQL variables

Easier to read and secure

$sql = "CALL my_proc('".$_GET['id']."');

$sql = "SET @id := '".$_GET['id']."'";mysqli_query($mid, $sql);$sql = "SELECT * FROM table WHERE id = @id"; mysqli_query($mid, $sql);

Injections are still possibles!!, just limited

Hidden entrances

MySQL logs (binary, slow, general)

SHOW PROCESSLIST

SHOW CREATE TABLE

Data folder

Backup systems (media, fichiers)

Replication slaves

Clients (history, network comm...)

Be preparedDelete unused data

Crypt data

Passwords, writeable but not readable

Poison your data

Audit critical data

Back up

Database security standards?

Sarbanes-Oxley, SOX

Health Insurance Portability and Accountability Act (HIPAA)

Payment Card Industry

Gramm-Leachy Bliley Act

SB 1386

BASEL II

Common vulnerabilities1)Insufficient security tests

2)Mediocre configuration

3)No encryption of critical data

4)No update processus

5)Security is called when a disaster strikes

6)No monitoring

7)Insufficient control over third parties access

1. Install and maintain a firewall configuration to protect cardholder data

2. Do not use vendor-supplied defaults for system passwords and other security parameters

3. Protect stored cardholder data

4. Encrypt transmission of cardholder data across open, public networks

5. Use and regularly update anti-virus software

6. Develop and maintain secure systems and applications

7. Restrict access to cardholder data by business need-to-know

8. Assign a unique ID to each person with computer access

9. Restrict physical access to cardholder data

10.Track and monitor all access to network resources and cardholder data

11.Regularly test security systems and processes

12.Maintain a policy that addresses information security

Norme PCI

Thanks http://www.nexen.net/

conferences.phpdamien.seguy@nexen.net