Oracle on Tuesday delivered 51 fixes in a quarterly patch distribution that included an updated scoring system for organisations to measure the risk and impact of vulnerabilities.

Twenty-seven patches correct vulnerabilities in the widely deployed Oracle Database Server, five of which are remotely exploitable.

The most severe bug contains a Common Vulnerability Scoring System (CVSS) version 2 rating of 6.5 out of 10.

CVSS version 2 was improved to make the scores more accurate, Eric Maurice, manager of security in Oracle's global technology business unit, said on the company's Global Product Security Blog.

"[It] is designed to address the criticism that CVSS scores tended to be clustered around few score values," Maurice wrote. "A number of new distinctions are introduced that result in further spreading the typical range of the CVSS 'base score' and making the standard more representative of real-world vulnerabilities."

That includes expanding the distinction of "access vectors" to better explain what access rights an attacker requires to exploit a vulnerability.

But Amachai Shulman, CTO of database security firm Imperva, said that the updated system fails to paint an accurate picture. He said some of the database server bugs that were patched are more severe than the scores might indicate.

The update also offered 11 fixes for the Application Server, eight for the E-Business Suite, three for PeopleSoft Enterprise and two for Enterprise Manager.