Database Security

David Nguyen

Dangers of Internet

Web based applications open up new threats to a corporation security

Protection of information is critical to success of a business

Analyzing the threat

Internet access Port access Server access Network access

Internet access

If hackers can guess the IP address of a server, they can telnet to the server and get a login prompt. At this point, all they need is a user ID and password to gain access to the server

Port access

All Web applications are configured to listen on a predefined port for incoming connections, and they generally use a listener daemon process to poll for connections.

Server access

A four-tiered Web application incorporates a series of Web servers, application servers, and database servers. Each of these servers presents a potential point of entry, and if remote shell access is enabled, a hacker that gets access to a single database may get access to many servers.

Network access

OracleNet, as an example, allows for incoming connect strings to the Oracle listener process. If hackers know the port, IP address, Oracle ID, and password, they can gain direct access to the database.

Countermeasures

Restricting server access Server account disabling Trusted IP addresses Restricting database access Authentication of users

Restricting server access

Some companies use domain servers to restrict server access to specified users. However, hackers still might intercept user IDs and passwords. To prevent this, many companies employ tools that utilise secure shell (ssh) technologies to encrypt external Internet communications.

Trusted IP addresses

UNIX servers are configured to answer only pings from a list of “trusted” hosts. In UNIX, one can restrict server access to a list of specific users

Server account disabling

If you suspend the server ID after three password attempts, attackers are thwarted. Without user ID suspension, an attacker can run a program that generates millions of passwords until it guesses the user ID and password combination.

Authentication of users

Kerberos security Virtual private databases Role-based security Grant-execute security Port access security

Kerberos security

Kerberos is a network authentication protocol. It is designed to provide strong authentication for client/server applications by using secret-key cryptography

Virtual private databases

VPD technology can restrict access to selected rows of tables

Role-based security

Object privileges can be grouped into roles, which can then be assigned to specific users

Grant-execute security

Execution privileges on procedures can be tightly coupled to users. When a user executes the procedures, they gain database access, but only within the scope of the procedure

Port access security

All Oracle applications are directed to listen at a specific port number on the server. Like any standard HTTP server, the Oracle Web Listener can be configured to restrict access

Conclusion

Allowing outside access to critical applications creates vulnerabilities to a company’s security

These threats need to be dealt with due to the importance of the information