Despite advertising claims by Oracle that its Oracle9i database is 'unbreakable', a UK security firm this week said it had found security holes in the software.

Several security flaws were discovered in the company's software, including one that could allow a hacker to gain access to Oracle's database server without a user ID or password.

The flaws were discovered by Next Generation Security Software in Sutton, Surrey. Oracle said yesterday that it was first informed about the flaws in December and has already made patches and workarounds available.

"No Oracle customers have reported issues stemming from these bugs," the company said in a statement.

David Litchfield, co-founder of Next Generation, gave details of the flaws on yesterday after announcing in December that he had discovered them.

Litchfield is expected to present a paper on his work at an upcoming Black Hat security conference, according to an Oracle spokeswoman.

The vulnerability that allows attackers to access a database server without authorisation also permits the attacker to execute a function in that software from a remote location. It affects Oracle9i and Oracle8i database servers running on all operating systems, according to the security advisory.

A second flaw could allow attackers to run arbitrary code or perform a DOS (denial of service) attack on the Oracle9i application server running on Sun's Solaris 2.6 operating system for Sparc processors, Microsoft's Windows NT and Windows 2000 Server operating systems, and HP's HP-UX version 11.0 operating system for 32bit operating systems, according to the advisory.

Another vulnerability enables an attacker to view the source code of JSPs (Java Server Pages) when they are downloaded from Oracle9i application servers running on all operating systems. Those files often display information such as the database user ID and password.

The security advisories are available at Next Generation Securities' website. Oracle has made patches and workarounds available online here.