About
Vulcan Cyber ExposureOS Risk Algorithm
Vulcan Cyber ExposureOS risk algorithm intelligently incorporates different contextual attributes to produce a dynamic risk score for each finding (instance) in your environment.
Our risk score is dynamic, personalized, and customizable. The platform allows you to:
Create your own risk model by setting weights for the different components of the algorithm
Customize your model with a Python script
Contact your CSM for Custom-Script support
To get started with custom Python scripts, contact your Customer Success Manager or Vulcan Cyber ExposureOS support at support@vulcan.io.
Script Basics
The script gets the input of 2 Python dictionaries - vulnerability_data and asset_data.
The script should return an integer between 0-100.
Configuration
Settings > Risk
Once the configuration is enabled by CSM, all weights in the UI should be set to 0, and the custom risk weight should be set to 1.
When Custom Risk Script is enabled, the vulnerability risk shows the following:
Expected Structure
def calculate_custom(vulnerability_data, asset_data):
**your script here**
Script Inputs
vulnerability_data
{
"id": {
"type": "integer"
},
"sources": {
"type": "string"
},
"cves": {
"type": "array",
"items": [{
"type": "string"
}
]
},
"cvss": {
"type": "number"
},
"cwes": {
"type": "array",
"items": {
"type": "integer"
}
},
"title": {
"type": "string"
},
"threats": {
"type": "array",
"items": [{
"type": "string"
}
]
},
“max_epss_score”: {
"type": “number”,
},
“cvss3_vector”: {
"type": “string”,
},
“temporal_cvss”: {
"type": “number”,
},
}
asset_data
{
"id": {
"type": "integer"
},
"ip": {
"type": "string"
},
"os": {
"type": "string"
},
"fqdn": {
"type": "string"
},
"tags": {
"type": "array",
"items": [{
"name": {
"type": "string"
},
"severity": {
"type": "integer"
}
}
]
},
"hostname": {
"type": "string"
},
"os_version": {
"type": "string"
},
"platform_family": {
"type": "string"
}
}
Notes
If an asset does not have tags,
tagswill beNoneand not an empty array.Non-host assets (Code Projects, Image, Websites) will only have the following fields:
id,name,tags.For EPSS score: If there is no score, it is Null. If the score is 0, it will return 0.
Example script
The script in this example boosts the score of exploitable vulnerabilities for affected assets with a specific tag.
def calculate_custom(vulnerability_data, asset_data):
if "Exploitable" in vulnerability_data['threats']:
if asset_data['tags']:
for tag in asset_data['tags']:
if tag['name'] == "MyTag":
return 100
return 0
FAQ
Can I manually edit the risk of vulnerability that has a custom risk score applied?
Yes. You can edit and override the risk provided based on the custom risk script parameters. See Editing risk manually.
Can I manually edit the parameters of the custom risk script?
No. To change the parameters or update the script, contact your Customer Success Manager at Vulcan Cyber ExposureOS.