Updated Proposal with private 0.0 - 10.0 cvssScoreType:
I hereby suggest to replace in vuln.xsd the hard wired V2/V3 mimic with the following:
A) Types for the vector (cvssVector) and the scale of the CVSS scalar scores (for v2/3 in [0.0, 10.0]):
A.1)
Only one type (which constrains the length to the maximum needed for v2 and v3) and hopefully the future versions.
String representing the components needed to compute the
various scores for CVSS versions 2 and 3. Note, that v3 scores can be longer than v2 scores
(up to 138 characters). It is assumed, that future versions of CVSS maintain the structure
of the information break down and the required vector length.
A.2)
New vuln:cvssScoreType compatible with the CVSS v2 and v3 decimal scores but private to CSAF CVRF.
This allows for decoupling of namespaces (no need to import cvss namespaces with specific schema versions anymore).
B) Only a ScoreSet but with a required Version attribute (xs:positiveInteger)
This will hold the CVSS version that the content conforms to.
Versions 2 and 3 fit the structure. It is assumed, that future versions 4, 5, ... will also fit.
C) The Container content of every [0, nifty] ScoreSet to be a sequence:
BaseScore (vuln:cvssScoreType) [1, 1]
TemporalScore (vuln:cvssScoreType) [0, 1]
EnvironmentalScore (vuln:cvssScoreType) [0, 1]
Vector (vuln:cvssVector) [0, 1]
vuln:ProductID [0, infty]
D) Change the path value of the selector in the uniqueness constraint UniqueScoreSetProductID into:
.//vuln:CVSSScoreSets/vuln:ScoreSet/vuln:ProductID
All in all this embraces the future in a reasonable way, and should allow for easy migration of older documents.
Details:
A)
A.1)
<xs:simpleType name="cvssVector">
<xs:annotation>
<xs:documentation xml:lang="en">String representing the components needed to compute the
various scores for CVSS versions 2 and 3. Note, that v3 scores can be longer than v2 scores
(up to 138 characters). It is assumed, that future versions of CVSS maintain the structure
of the information break down and the required vector length.</xs:documentation>
</xs:annotation>
<xs:restriction base="xs:token">
<xs:maxLength value="140"/>
</xs:restriction>
</xs:simpleType>
A.2)
<xsd:simpleType name="cvssScoreType">
<xsd:annotation>
<xsd:documentation>Value restriction to single decimal values from 0.0 to 10.0, as used in CVSS scores</xsd:documentation>
</xsd:annotation>
<xsd:restriction base="xsd:decimal">
<xsd:minInclusive value="0"/>
<xsd:maxInclusive value="10"/>
<xsd:fractionDigits value="1"/>
</xsd:restriction>
</xsd:simpleType>
B) and C)
<xs:element name="ScoreSet" minOccurs="0" maxOccurs="unbounded">
<xs:annotation>
<xs:documentation xml:lang="en">CVSS scores for a given product ID. If the
ProductID attribute is omitted, the score applies to all vulnerable
products.</xs:documentation>
</xs:annotation>
<xs:complexType>
<xs:sequence>
<xs:element name="BaseScore" type="vuln:cvssScoreType" minOccurs="1"
maxOccurs="1">
<xs:annotation>
<xs:documentation xml:lang="en">The CVSS Base Score is the numeric value of
the computed CVSS Base Score which should be a float from 0 –
10.0.</xs:documentation>
</xs:annotation>
</xs:element>
<xs:element name="TemporalScore" type="vuln:cvssScoreType"
minOccurs="0" maxOccurs="1">
<xs:annotation>
<xs:documentation xml:lang="en">The CVSS Base Score is the numeric value of
the computed CVSS Temporal Score which should be a float from 0 –
10.0.</xs:documentation>
</xs:annotation>
</xs:element>
<xs:element name="EnvironmentalScore" type="vuln:cvssScoreType"
minOccurs="0" maxOccurs="1">
<xs:annotation>
<xs:documentation xml:lang="en">The CVSS Base Score is the numeric value of
the computed CVSS Environmental Score which should be a float from 0 –
10.0.</xs:documentation>
</xs:annotation>
</xs:element>
<xs:element name="Vector" type="vuln:cvssVector" minOccurs="0" maxOccurs="1">
<xs:annotation>
<xs:documentation xml:lang="en">The CVSS Vector string is the official
notation that contains all of the values used to compute the Base,
Temporal, and Environmental scores.</xs:documentation>
</xs:annotation>
</xs:element>
<xs:element ref="vuln:ProductID" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="Version" type="xs:positiveInteger" use="required">
<xs:annotation>
<xs:documentation xml:lang="en">The CVSS version that the content
conforms to. Versions 2 and 3 fit the structure. It is assumed, that
future versions 4, 5, ... will also fit.</xs:documentation>
</xs:annotation>
</xs:attribute>
</xs:complexType>
</xs:element>
D)
<xs:unique name="UniqueScoreSetProductID">
<xs:annotation>
<xs:documentation xml:lang="en">This is to ensure that each CVSS score set mentions a given
ProductID only one.</xs:documentation>
</xs:annotation>
<xs:selector xpath=".//vuln:CVSSScoreSets/vuln:ScoreSet/vuln:ProductID"/>
<xs:field xpath="."/>
</xs:unique>
Improvement
Critical