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Added CVSSv4 support #166

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Added CVSSv4 support #166

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1 change: 1 addition & 0 deletions docs/schema.md
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Original file line number Diff line number Diff line change
Expand Up @@ -433,6 +433,7 @@ describes the quantitative method used to calculate the associated `score`.
| --------- | ----------- |
| `CVSS_V2` | A CVSS vector string representing the unique characteristics and severity of the vulnerability using a version of the [Common Vulnerability Scoring System notation](https://www.first.org/cvss/v2/) that is == 2.0 (e.g.`"AV:L/AC:M/Au:N/C:N/I:P/A:C"`).|
| `CVSS_V3` | A CVSS vector string representing the unique characteristics and severity of the vulnerability using a version of the [Common Vulnerability Scoring System notation](https://www.first.org/cvss/) that is >= 3.0 and < 4.0 (e.g.`"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N"`).|
| `CVSS_V4` | A CVSS vector string representing the unique characteristics and severity of the vulnerability using a version of the [Common Vulnerability Scoring System notation](https://www.first.org/cvss/) that is >= 4.0 and < 5.0 (e.g.`"CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/S:X/AU:X/R:X/V:X/RE:X/U:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/CR:X/IR:X/AR:X/E:X"`).|
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Just a question:

https://www.first.org/cvss/v4.0/specification-document states:

"A vector string must contain metrics in the order shown in Table 23, every other ordering is invalid. All Base metrics must be included in a vector string."

The example vector string here doesn't seem to follow the order in table 23 of the spec. e.g. "Exploit Maturity (E)" is listed in the middle of the table, but is the last metric in the example vector string.

Am I reading the spec correctly here?

This seems different from CVSS 3.x (which states "A vector string should contain metrics in the order shown in Table 15, though other orderings are valid."). We had to remove our regex validation because of that (#168).

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For the reason you pointed out, we had to change the fixed ordering rule. Indeed, building a CVSS v4.0-compliant regular expression imply testing O(n!) combinations, and with 32 unique metrics... The regex would be Terrabytes long 😅

The documented CVSS v4.0 vector/string representation here is invalid as the group order is BTES, not BSTE. The valid vector must be CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

| Your quantitative severity type here. | [Send us a PR](https://github.com/ossf/osv-schema/compare). |

### severity[].score field
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19 changes: 18 additions & 1 deletion validation/schema.json
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Expand Up @@ -289,7 +289,8 @@
"type": "string",
"enum": [
"CVSS_V2",
"CVSS_V3"
"CVSS_V3",
"CVSS_V4"
]
},
"score": {
Expand Down Expand Up @@ -328,6 +329,22 @@
}
}
}
},
{
"if": {
"properties": {
"type": {
"const": "CVSS_V4"
}
}
},
"then": {
"properties": {
"score": {
"pattern": "CVSS:4\\.[0-9]\\/AV:[NALP]\\/AC:[LH]\\/AT:[NP]\\/PR:[NLH]\\/UI:[NPA](\\/VC:[HLN]\\/VI:[HLN]\\/VA:[HLN]\\/SC:[HLN]\\/SI:[HLN]\\/SA:[HLN])?\\/S:[XNP]\\/AU:[XNY]\\/R:[XAUI]\\/V:[XDC]\\/RE:[XLMH]\\/U:[XCGAR]\\/MAV:[XNALP]\\/MAC:[XLH]\\/MAT:[XNP]\\/MPR:[XNLH]\\/MUI:[XNPA]\\/MVC:[XHLN]\\/MVI:[XHLN]\\/MVA:[XHLN]\\/MSC:[XHLN]\\/MSI:[XSHLN]\\/MSA:[XSHLN]\\/CR:[XHML]\\/IR:[XHML]\\/AR:[XHML]\\/E:[XAPU]"
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Same comment re ordering here. We also need to make sure the metrics listed as optional in the spec are actually optional here (per table 23 in https://www.first.org/cvss/v4.0/specification-document).

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I recommend using the official regular expression that is fully compliant with the specification here.

}
}
}
}
],
"required": [
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