Fix calculation bug in CVSS3

Author: vmayoral

cvsslib/cvss3/calculations.py

@@ -3,6 +3,7 @@
 from .enums import *
 from decimal import Decimal as D
 from cvsslib.base_enum import NotDefined
+import decimal
 
 
 EXPLOITABILITY_COEFFECIENT = D("8.22")
@@ -59,9 +60,9 @@ def calculate_modified_impact_sub_score(scope: ModifiedScope,
     )
 
     if scope == ModifiedScope.UNCHANGED.value:
-        return IMPACT_UNCHANGED_COEFFECIENT * modified
+        return IMPACT_UNCHANGED_COEFFECIENT * decimal.Decimal(modified)
     else:
-        return IMPACT_CHANGED_COEFFECIENT * (modified - D("0.029")) - D("3.25") * D(math.pow(modified - D(0.02), 15))
+        return IMPACT_CHANGED_COEFFECIENT * (decimal.Decimal(modified) - D("0.029")) - D("3.25") * D(math.pow(decimal.Decimal(modified) - D(0.02), 15))
 
 
 def calculate_base_score(run_calculation, scope: Scope, privilege: PrivilegeRequired):
@@ -144,4 +145,4 @@ def calculate(run_calculation, get):
 
     environment_score = run_calculation(calculate_environmental_score, override=override)
 
-    return float(base_score), float(temporal_score), float(environment_score)
+    return float(base_score), float(temporal_score), float(environment_score)