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Oracle releases MySQL security vulnerability fixes 2018-01

As in every quarter of the year Oracle has released yesterday its recommendation for the MySQL security updates. This is called, in Oracle terminology, Critical Patch Update (CPU) Advisory.

This CPU is published for all Oracle products. But FromDual is only interested in MySQL related topics. So let us concentrate on those.

This time 25 fixes with a maximum score of 8.1 (out of 10.0) were published.

6 of theses 25 vulnerabilities are exploitable remotely over the network without authentication (no user credentials required)!

The following MySQL products are affected:

  • MySQL Enterprise Monitor ( and before, and before, and before)
  • MySQL Connector/Net (6.9.9. and before, 6.10.4 and before)
  • MySQL Connector/ODBC (5.3.9. and before)
  • MySQL Server (5.5.58 and before, 5.6.38 and before, 5.7.19 and before)

It is recommended to upgrade your MySQL products to close the security vulnerabilities.

FromDual upgrade decision aid

Because such security updates are published quarterly and some of our customers have dozens to hundreds of MySQL installations this would end up in a never ending story where you are continuously upgrading MySQL database servers and other products.

This led to idea to create an upgrade decision aid to decide if you have to upgrade to this CPU or not.

The following questions can be asked:

  • How exposed is your database?
    Databases can be located in various network segments. It is not recommended to expose databases directly to the internet. Databases are either installed in demilitarized zones (DMZ) with no direct access from the internet or in the companies private network (only company employees should be able to access the database) or even specialized secure networks (only a limited number of specific employees can access this network).
  • How critical are your data?
    Some data are more interesting or critical, some data are less interesting or critical. Interesting data are: User data (user name and password), customer data (profiles, preferences, etc.), financial data (credit cards) and health care data (medical data). Systems containing such data are more critical than others. You can also ask: How sever is it if such data leak?
  • How broad is the user base able to access the database?
    How many employees do you have in your company? How many contractors do you have in your company? How many employees have physical access to the database server? How good is the mood of those people?
    How good are the user credentials to protect your database? Do you have shared passwords or no passwords at all? Do you have an account management (expiring old accounts, rotate passwords from time to time)?
    How much do you trust your users? Do you trust all your employees? Do you trust only admins? Or do you not even trust your admins?
  • How severe are the security vulnerabilities?
    You can define a threshold of severity of the vulnerabilities above you want to take actions. According to your criticality you can take actions for example as follows: Greater or equal than 7.5 if you have less critical data. Greater or equal than 6.0 if you have critical data.
  • Can the vulnerability be use from remote (over the network) and does it need a user authentication to exploit the vulnerability? What products (MySQL Enterprise Monitor, MySQL Server, MySQL Connectors) and what modules (Apache/Tomcat, .Net Connector, Partitioning, Stored Procedures, InnoDB, DDL, GIS, Optimizer, ODBC, Replication, DML, Performance Schema) are affected?

Depending on your readiness to take a risk you get now answers to decide if you have to take actions or not.

Some examples

  • Situation: Your database is exposed directly to the internet or you forgot to install some firewall rules to protect your MySQL port.
    Analysis: You are probably affected by CVE-2018-2696 and CVE-2017-3737 (score 5.9 and 7.5). So you passed the threshold for non-critical data (7.5) and nearly passed the threshold for critical data (6.0). These vulnerabilities allow attacks over the network without user authentication.
    Action: Immediate upgrade is recommended. Mid-term action: Install firewall rules to protect your MySQL to avoid access from remote and/or do not expose databases directly to the internet.
  • Situation: Your database is located in the intranet zone. You have slack user/password policies and you have many employees and also many contractors from foreign countries working on various projects. And you have very sensitive/interesting financial data stored in your database.
    Analysis: Many people, not all of them are really trusted, have network access to the database. It is quite possible that passwords have been shared or people have passwords for projects they are not working for any more. You are affected by nearly all of the vulnerabilities (network).
    Action: You should plan an upgrade soon. Mid-term action: Try to restrict access to the databases and implement some password policy rules (no shared passwords, password expiration, account locking etc.).
  • Situation: Your highly critical databases are located in a specially secured network and only applications, Linux admins and DBAs have access to this network. And you completely trust those people.
    Analysis: Your threshold is 6.0 and (unauthenticated) attack over the network is not possible. There are some vulnerabilities of which you are affected but the database is only accessed by an application. So those vulnerabilities cannot be exploited easily.
    Action: You possibly can ignore this CPU for the MySQL database this time. But you have a vulnerability in the .Net Connector (Connector/Net). If an attacker exploits the vulnerability on the Connector he possibly can get access to the data. So you have to upgrade the Connector of your application accessing the database.

If you follow the ideas of this aid you will probably have one or two upgrades a year. And this you should do anyway just to stay up to date...

See also Common Vulnerability Scoring System Version 3.0 Calculator.

Taxonomy upgrade extras: