Establishing Vulnerability Response Calculator Rule for Credential scan host coming from Tenable

[GauravT47983100]

Hello Community!

I am reaching out to get some assistance with establishing Vulnerability response calculator rule to calculate weighted average score from the severity of the identified credential host from Tenable to ServiceNow.

I want to use this formula where let's say-

Findings and host scanned totals to 115 Hosts, and

- Severity of Critical and high finding1 = 10

- Severity of Medium findings2 = 504

- Severity of Low findings3 = 3000

therefore finding per host ---

Critical and high Finding1 = 10/115 = 0.09 | Medium  Finding2= 504/115 = 4.38 | Low Finding3 = 3000/115 = 26.09 and,  therefore according to formula,

where weighted = (10/4/1) total of 15

Weighed Average = (0.09 * 10 + 4.38 * 4 + 26.09 *1 ) / 15  = 2.97

So, if finding per host is >= 2.5 than its considered Moderate Severity and if Weighted Average is >= 3.5 is considered as Vulnerability with Critical-1 Severity

Now, I wanted to understand how I can use this formula to implement in my Vulnerability Response Calculator!! Has anyone applied such cases in their Vulnerability Response Project or so with Tenable Integration?

[MiravTMehta]

Great query. This is completely doable in ServiceNow VR through a script‑based Vulnerability Calculator Rule ; implementation aligns with what the VR documentation calls a "script‑based" calculator rule. Would recommend reaching out to your implementation partner or servicenow champion to help you build the script based on above conditional statements. 

On high level

Navigate to:

• Vulnerability Response → Administration -> Vulnerability Calculators
• Add a Calculator Rule (Script Condition)
• Use Script to Perform Weighted Average Calculation