PSCVSS

2.0.1

Class/PSCVSS.Classes.ps1

class BaseScore {
    [Single] $AttackVector = 1
    [Single] $AttackComplexity = 1
    [Single] $PrivilegeRequired = 1
    [Single] $UserInteraction = 0.85
    [Single] $Scope = 1
    [Single] $Confidentiality = 1
    [Single] $Integrity = 1
    [Single] $Availability = 1
    [Double] $ExploitabilitySubScore
    [Double] $ImpactSubScoreBaseScore
    [Double] $ImpactSubScore
    [Double] $BaseScore


    BaseScore() {
    }

    [Void] CalculateExploitabilitySubScore (){
        $this.ExploitabilitySubScore = [Single] 8.22 * $this.AttackVector * $this.AttackComplexity * $this.PrivilegeRequired * $this.UserInteraction
    }

    [Double] GetExploitabilitySubScore(){
        return $this.ExploitabilitySubScore
    }

    [Void] CalculateImpactSubScoreBaseScore (){
        $this.ImpactSubScoreBaseScore = (1 - ((1 - $this.Confidentiality) * (1 - $this.Integrity) * (1 - $this.Availability)))
    }

    [Double] GetImpactSubScoreBaseScore (){
        return $this.ImpactSubScoreBaseScore
    }

    [Void] CalculateImpactSubScore (){
        if ($this.Scope -eq 6.42){
            $this.ImpactSubScore = $this.Scope * $this.ImpactSubScoreBaseScore
        }
        else{
            $this.ImpactSubScore = $this.Scope * ($this.ImpactSubScoreBaseScore - 0.029) - 3.25 * [Math]::Pow(($this.ImpactSubScoreBaseScore - 0.02), 15)
        }
    }

    [Double] GetImpactSubScore (){
        return $this.ImpactSubScore
    }

    [Void] CalculateBaseScore (){
        if ($this.ImpactSubScore -le 0){
            $this.BaseScore = 0
        }
        else{
            if ($this.Scope -eq 6.42){
                $this.BaseScore = [Math]::Min($this.ExploitabilitySubScore + $this.ImpactSubScore, 10)
            }
            else{
                $this.BaseScore = [Math]::Min(($this.ExploitabilitySubScore + $this.ImpactSubScore) * 1.08, 10)
            }
        }        
    }

    [Double] GetBaseScore (){
        return [Math]::Ceiling($this.BaseScore * [Math]::Pow(10, 1)) / [Math]::Pow(10,1)
    }

    [Void] CalculateScore(){
        $this.CalculateExploitabilitySubScore()
        Write-Debug -Message "Base Exploitability Sub Score is $($this.ExploitabilitySubScore)"

        $this.CalculateImpactSubScoreBaseScore()
        Write-Debug -Message "Base Impact Sub Score Base Score is $($this.ImpactSubScoreBaseScore)"
        
        $this.CalculateImpactSubScore()
        Write-Debug -Message "Base Impact Sub Score is $($this.ImpactSubScore)"

        $this.CalculateBaseScore()
        Write-Debug -Message "Base Score is $($this.BaseScore)"
    }
}


class EnvironmentalScore {
    [Single] $ConfidentialityRequirement = 1
    [Single] $IntegrityRequirement = 1
    [Single] $AvailabilityRequirement = 1
    [Single] $ModifiedAttackVector = 1
    [Single] $ModifiedAttackComplexity = 1
    [Single] $ModifiedPrivilegesRequired = 1
    [Single] $ModifiedUserInteraction = 1
    [Single] $ModifiedScope = 1
    [String] $ModifiedScopeStatus = 'Unchanged'
    [Single] $ModifiedConfidentiality = 1
    [Single] $ModifiedIntegrity = 1
    [Single] $ModifiedAvailability = 1

    [Double] $ModifiedExploitabilitySubScore
    [Double] $ModifiedImpactMULScore
    [Double] $ModifiedImpactSubScore
    [Double] $ModifiedBaseSubScore
    [Double] $CVSSScore


    EnvironmentalScore() {
    }

    [String] getFormattedValue($value){
        $intNumber = ($value).ToString().Split('.')[0]
        $decNumber = ($value).ToString().Split('.')[1][0]
        return "$intNumber.$decNumber"
    }

    [Void] CalculateModifiedExploitabilitySubScore(){
        $this.ModifiedExploitabilitySubScore = 8.22 * $this.ModifiedAttackVector * $this.ModifiedAttackComplexity * $this.ModifiedPrivilegesRequired * $this.ModifiedUserInteraction
    }

    [Double] GetModifiedExploitabilitySubScore(){
        return $this.ModifiedExploitabilitySubScore
    }

    [Void] CalculateModifiedImpactMULScore (){
        $this.ModifiedImpactMULScore = [Math]::Min((1 - (1 - $this.ModifiedConfidentiality * $this.ConfidentialityRequirement) * (1 - $this.ModifiedIntegrity * $this.IntegrityRequirement) * (1 - $this.ModifiedAvailability * $this.AvailabilityRequirement)), 0.915)
    }

    [Double] GetModifiedImpactMULScore (){
        return $this.ModifiedImpactMULScore
    }

    [Void] CalculateModifiedImpactSubScore(){
        if (($this.ModifiedScope -eq 6.42) -or ($this.ModifiedScopeStatus -eq 'Unchanged')){
            $this.ModifiedImpactSubScore = $this.ModifiedScope * $this.ModifiedImpactMULScore
        }
        else{
            $this.ModifiedImpactSubScore = $this.ModifiedScope * ($this.ModifiedImpactMULScore - 0.029) - 3.25 * [Math]::Pow(($this.ModifiedImpactMULScore - 0.02), 15)
        }
    }

    [Double] GetModifiedImpactSubScore(){
        return $this.ModifiedImpactSubScore
    }

   [Void] CalculateModifiedBaseSubScore([Single]$exploitCodeMaturityScore, [Single]$remediationLevel, [Single]$reportConfidence){
        if ($this.ModifiedImpactSubScore -le 0){
            $this.ModifiedBaseSubScore = 0
        }
        else{
            if (($this.ModifiedScope -eq 6.42) -or ($this.ModifiedScopeStatus -eq 'Unchanged')){
                $this.ModifiedBaseSubScore = [Math]::Round([Math]::Min( ($this.ModifiedExploitabilitySubScore + $this.ModifiedImpactSubScore), 10), 1) * $exploitCodeMaturityScore * $remediationLevel * $reportConfidence
            }
            else{
                $this.ModifiedBaseSubScore = [Math]::Round([Math]::Min((($this.ModifiedExploitabilitySubScore + $this.ModifiedImpactSubScore) * 1.08), 10), 1) * $exploitCodeMaturityScore * $remediationLevel * $reportConfidence
            }
        }
    }

    [Double] GetModifiedBaseSubScore(){
        return $this.getFormattedValue($this.ModifiedBaseSubScore)
    }

    [Void] CalculateCVSSScore(){
        $this.CVSSScore = $this.ModifiedBaseSubScore * 10 / 10
    }

    [Double] GetCVSSScore(){
        return $this.getFormattedValue($this.CVSSScore)
    }

    [Void] CalculateScore([Single]$exploitCodeMaturityScore, [Single]$remediationLevel, [Single]$reportConfidence){
        $this.CalculateModifiedExploitabilitySubScore()
        Write-Debug -Message "Base Exploitability Sub Score is $($this.ModifiedExploitabilitySubScore)"

        $this.CalculateModifiedImpactMULScore()
        Write-Debug -Message "Base Impact Sub Score Base Score is $($this.ModifiedImpactMULScore)"
        
        $this.CalculateModifiedImpactSubScore()
        Write-Debug -Message "Base Impact Sub Score is $($this.ModifiedImpactSubScore)"

        $this.CalculateModifiedBaseSubScore($exploitCodeMaturityScore, $remediationLevel, $reportConfidence)
        Write-Debug -Message "Base Score is $($this.ModifiedBaseSubScore)"

        $this.CalculateCVSSScore()
        Write-Debug -Message "CVSS Score is $($this.CVSSScore)"
    }
}


class TemporalScore {
    [Single] $ExploitCodeMaturity = 1
    [Single] $RemediationLevel = 1
    [Single] $ReportConfidence = 1
    
    [Double] $TemporalScore

    TemporalScore() {
    }

    [Void] CalculateTemporalScore ([Double] $baseScore){
        $this.TemporalScore = [Math]::Round(($baseScore * $this.ExploitCodeMaturity * $this.RemediationLevel * $this.ReportConfidence), 1)
    }

    [Double] GetTemporalScore (){
        return $this.TemporalScore
    }
}