Oracle may be subtly misleading customers about the severity of some of the vulnerabilities found in its database software, according to researchers from database security software provider Application Security (AppSec).
"Oracle likes to downplay the risk of its vulnerabilities," said Alex Rothacker, director of security research for AppSec. As a result, organisations using Oracle's vulnerability ratings to prioritise system updates may unduly delay applying some critical patches, he said.
Every three months, Oracle bundles and releases patches to fix recently discovered vulnerabilities in its software products. The company rates the severity of these vulnerabilities using the Common Vulnerability Scoring System (CVSS) industry standard.
AppSec's concern centres around a unique rating that Oracle has added onto its CVSS scores, called Partial+. A CVSS rating is single score, ranging form 1 to 10, that summarizes the severity of a vulnerability. The score itself is an average of a set of scores that evaluate the different aspects of a vulnerability's severity.
One subset of the CVSS scores evaluates how much damage could be caused by malicious software based on the vulnerability. If such malicious software, called an exploit, could only damage the software it attacks, it would typically be given a Partial rating. But if the exploit could wreak havoc on the underlying system, then it would be given a rating of Complete, which carries with it a higher number.
"In its scoring, Oracle will hardly ever use the Complete," Rothacker said. In many cases, Oracle will use the its own Partial+ rating, which in Oracle's calculations, equals a Partial rating, he sad. In some cases, Oracle will use the Partial+ rating for a database vulnerability, which Rothacker describes a system-level vulnerability, he added.
"The truth is if you run an Oracle database on a server, you will not run SharePoint on the same server. You will have a dedicated database server," Rothacker said.
Oracle does acknowledge that some users may want to recalculate the CVSS ratings if a Partial+ is applied to software in their environments.
In a recent blog post Oracle software security assurance director Eric Maurice said that Oracle recognises that some companies may choose to "discretely inflate the Base Score when a value of Partial + is reported by Oracle".
Oracle officials declined to comment on the issue for this story.
Many organisations rely on the CVSS scores in order to determine which patches they should apply first. In enterprise environments, applying a patch to some software involves extensive testing to ensure the updated software works correctly with its surrounding environments.
"It's very hard for an organisation to have all of its systems patched. So an organisation will prioritise its patches, ranking them by severity. It will take care of the really bad ones first," Rothacker said.
As an example of the discrepancy Partial+ can bring about, Rothacker points to a pair of nearly identical vulnerabilities found in the network stack of the Oracle database, both discovered by an AppSec researcher. Oracle assigned one vulnerability a CVSS rating of five and the other a more severe rating CVSS rating of 7.8, even though the two vulnerabilities differed from one another by only one byte, explained security researcher Esteban Martinez Fayo, in a blog post. The chief difference between the two ratings stemmed from the fact that one ranked with lower severity was given a Partial+ rating while the other one was assigned a Complete.
Of course, AppSec has a vested interest in having security officers revaluate Oracle's own vulnerability reports. The company offers auditing and compliance software for judging database security, and even offers its own revised severity ratings for Oracle database vulnerabilities. But the company does have intimate knowledge of Oracle vulnerabilities: its researchers found four of the six database vulnerabilities Oracle addressed in its last patch update.
AppSec is not alone in questioning Oracle's unique Partial+ rating.
By creating the Partial+ rating, Oracle is in effect creating its own measurement system, said Adrian Lane, chief technology officer and analyst for security research firm Securosis. Lane, who also addressed the issue in a recent blog post, noted that while CVSS provides only an approximation of how severe a vulnerability can be, it is still a useful metric to administrators.
"By altering basic CVSS metrics, Oracle is throwing out the standard yardstick," he said.
Lane agrees with Rothacker's assessment that a vulnerability affecting all the tables of a database is a system-level vulnerability. If the vulnerability only affects a few tables, then it should be considered a Partial vulnerability, but by having control over an entire database, an exploit could disrupt the entire platform, and be given a Complete, he said.