The ratings will consist of three numbers, Gerhard Eschelbeck, the chief technology officer at security information provider Qualys said on Tuesday.
The first will be a baseline estimate of the severity of the flaw. The second will rate the bug depending on how long it has been around, and therefore how likely it is that companies have patched against it. The third will measure the threat a vulnerability poses to a specific corporate network. Each will take five or six factors into account for the measurement.
The companies plan to announce the first version of the system on Thursday, Eschelbeck said. They are proposing that vulnerability trackers such as BugTraq use the approach to label the severity of new software bugs. Businesses can take the ratings to calculate the level of risk on their own network, to generate a single grade, depending on factors such as how reliant they are on the affected software.
"There are three numbers, but customers will deal with a specific final number," he said. "You can see right out of the get-go how vulnerable you are."
The launch, which will be made at the RSA Conference 2005 here this week, is the fruit of a partnership of Redwood Shores, Calif.-based Qualys, networking giant Cisco and security company Symantec. It is designed to provide the first systematic grading of flaws that can be used by companies to assess damage to their vulnerable systems and to.
The ratings could also on the different computing platforms, such as Microsoft Windows, the open-source Linux and Apple Computer's Mac OS X.