Add exclude severity filter

v2/cmd/nuclei/main.go

@@ -71,6 +71,7 @@ on extensive configurability, massive extensibility and ease of use.`)
 		flagSet.StringSliceVarP(&options.ExcludedTemplates, "exclude", "exclude-templates", []string{}, "template or template directory paths to exclude"),
 
 		flagSet.VarP(&options.Severities, "impact", "severity", fmt.Sprintf("Templates to run based on severity. Possible values: %s", severity.GetSupportedSeverities().String())),
+		flagSet.VarP(&options.ExcludeSeverities, "exclude-impact", "exclude-severity", fmt.Sprintf("Templates to exclude based on severity. Possible values: %s", severity.GetSupportedSeverities().String())),
 		flagSet.NormalizedStringSliceVar(&options.Author, "author", []string{}, "execute templates that are (co-)created by the specified authors"),
 	)
 

v2/internal/runner/runner.go

@@ -344,6 +344,7 @@ func (r *Runner) RunEnumeration() error {
 		IncludeTemplates:   r.options.IncludeTemplates,
 		Authors:            r.options.Author,
 		Severities:         r.options.Severities,
+		ExcludeSeverities:  r.options.ExcludeSeverities,
 		IncludeTags:        r.options.IncludeTags,
 		TemplatesDirectory: r.options.TemplatesDirectory,
 		Catalog:            r.catalog,

v2/pkg/catalog/loader/filter/tag_filter.go

@@ -9,11 +9,12 @@ import (
 
 // TagFilter is used to filter nuclei templates for tag based execution
 type TagFilter struct {
-	allowedTags map[string]struct{}
-	severities  map[severity.Severity]struct{}
-	authors     map[string]struct{}
-	block       map[string]struct{}
-	matchAllows map[string]struct{}
+	allowedTags       map[string]struct{}
+	severities        map[severity.Severity]struct{}
+	excludeSeverities map[severity.Severity]struct{}
+	authors           map[string]struct{}
+	block             map[string]struct{}
+	matchAllows       map[string]struct{}
 }
 
 // ErrExcluded is returned for excluded templates
@@ -54,15 +55,21 @@ func (tagFilter *TagFilter) Match(templateTags, templateAuthors []string, templa
 }
 
 func isSeverityMatch(tagFilter *TagFilter, templateSeverity severity.Severity) bool {
-	if len(tagFilter.severities) == 0 || templateSeverity == severity.Undefined {
+	if (len(tagFilter.excludeSeverities) == 0 && len(tagFilter.severities) == 0) || templateSeverity == severity.Undefined {
 		return true
 	}
 
-	if _, ok := tagFilter.severities[templateSeverity]; ok {
-		return true
+	included := true
+	if len(tagFilter.severities) > 0 {
+		_, included = tagFilter.severities[templateSeverity]
 	}
 
-	return false
+	excluded := false
+	if len(tagFilter.excludeSeverities) > 0 {
+		_, excluded = tagFilter.excludeSeverities[templateSeverity]
+	}
+
+	return included && !excluded
 }
 
 func isAuthorMatch(tagFilter *TagFilter, templateAuthors []string) bool {
@@ -110,23 +117,25 @@ func isTagMatch(tagFilter *TagFilter, templateTags []string) bool {
 }
 
 type Config struct {
-	Tags        []string
-	ExcludeTags []string
-	Authors     []string
-	Severities  severity.Severities
-	IncludeTags []string
+	Tags              []string
+	ExcludeTags       []string
+	Authors           []string
+	Severities        severity.Severities
+	ExcludeSeverities severity.Severities
+	IncludeTags       []string
 }
 
 // New returns a tag filter for nuclei tag based execution
 //
-// It takes into account Tags, Severities, Authors, IncludeTags, ExcludeTags.
+// It takes into account Tags, Severities, ExcludeSeverities, Authors, IncludeTags, ExcludeTags.
 func New(config *Config) *TagFilter {
 	filter := &TagFilter{
-		allowedTags: make(map[string]struct{}),
-		authors:     make(map[string]struct{}),
-		severities:  make(map[severity.Severity]struct{}),
-		block:       make(map[string]struct{}),
-		matchAllows: make(map[string]struct{}),
+		allowedTags:       make(map[string]struct{}),
+		authors:           make(map[string]struct{}),
+		severities:        make(map[severity.Severity]struct{}),
+		excludeSeverities: make(map[severity.Severity]struct{}),
+		block:             make(map[string]struct{}),
+		matchAllows:       make(map[string]struct{}),
 	}
 	for _, tag := range config.ExcludeTags {
 		for _, val := range splitCommaTrim(tag) {
@@ -140,6 +149,11 @@ func New(config *Config) *TagFilter {
 			filter.severities[tag] = struct{}{}
 		}
 	}
+	for _, tag := range config.ExcludeSeverities {
+		if _, ok := filter.excludeSeverities[tag]; !ok {
+			filter.excludeSeverities[tag] = struct{}{}
+		}
+	}
 	for _, tag := range config.Authors {
 		for _, val := range splitCommaTrim(tag) {
 			if _, ok := filter.authors[val]; !ok {

v2/pkg/catalog/loader/filter/tag_filter_test.go

@@ -73,6 +73,16 @@ func TestTagBasedFilter(t *testing.T) {
 		matched, _ := filter.Match([]string{"fuzz"}, []string{"pdteam"}, severity.High, nil)
 		require.True(t, matched, "could not get correct match")
 	})
+	t.Run("match-exclude-severity", func(t *testing.T) {
+		filter := New(&Config{
+			ExcludeSeverities: severity.Severities{severity.Low},
+		})
+		matched, _ := filter.Match([]string{"fuzz"}, []string{"pdteam"}, severity.High, nil)
+		require.True(t, matched, "could not get correct match")
+
+		matched, _ = filter.Match([]string{"fuzz"}, []string{"pdteam"}, severity.Low, nil)
+		require.False(t, matched, "could not get correct match")
+	})
 	t.Run("match-exclude-with-tags", func(t *testing.T) {
 		filter := New(&Config{
 			Tags:        []string{"tag"},

v2/pkg/catalog/loader/loader.go

@@ -19,11 +19,12 @@ type Config struct {
 	ExcludeTemplates []string
 	IncludeTemplates []string
 
-	Tags        []string
-	ExcludeTags []string
-	Authors     []string
-	Severities  severity.Severities
-	IncludeTags []string
+	Tags              []string
+	ExcludeTags       []string
+	Authors           []string
+	Severities        severity.Severities
+	ExcludeSeverities severity.Severities
+	IncludeTags       []string
 
 	Catalog            *catalog.Catalog
 	ExecutorOptions    protocols.ExecuterOptions
@@ -49,11 +50,12 @@ func New(config *Config) (*Store, error) {
 	store := &Store{
 		config: config,
 		tagFilter: filter.New(&filter.Config{
-			Tags:        config.Tags,
-			ExcludeTags: config.ExcludeTags,
-			Authors:     config.Authors,
-			Severities:  config.Severities,
-			IncludeTags: config.IncludeTags,
+			Tags:              config.Tags,
+			ExcludeTags:       config.ExcludeTags,
+			Authors:           config.Authors,
+			Severities:        config.Severities,
+			ExcludeSeverities: config.ExcludeSeverities,
+			IncludeTags:       config.IncludeTags,
 		}),
 		pathFilter: filter.NewPathFilter(&filter.PathFilterConfig{
 			IncludedTemplates: config.IncludeTemplates,

v2/pkg/types/types.go

@@ -25,6 +25,8 @@ type Options struct {
 	Vars goflags.RuntimeMap
 	// Severities filters templates based on their severity and only run the matching ones.
 	Severities severity.Severities
+	// ExcludeSeverities specifies severities to exclude
+	ExcludeSeverities severity.Severities
 	// Author filters templates based on their author and only run the matching ones.
 	Author goflags.NormalizedStringSlice
 	// IncludeTags includes specified tags to be run even while being in denylist