[BUG] panic SIGSEGV while running nuclei go library with headless screenshot template

[rootxjs]

Is there an existing issue for this?

• I have searched the existing issues.

Current Behavior

Getting panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV:segmentation violation code=0x2 addr=0x8 pc=0x1021c5600]

While running nuclei go library with headless template

Expected Behavior

Run the headless screenshot template and return the output

Steps To Reproduce

1. Run the nuclei headless template using nuclei sdk

ctx := context.Background()
	ne, err := nuclei.NewThreadSafeNucleiEngineCtx(ctx,
		// nuclei.WithVerbosity(nuclei.VerbosityOptions{
		// 	Verbose: true,
		// 	Debug:   true,
		// }),
		nuclei.EnableHeadlessWithOpts(&nuclei.HeadlessOpts{
			PageTimeout: 30,
			ShowBrowser: false,
			UseChrome:   false,
		}),
	)
	if err != nil {
		panic(err)
	}
	// setup waitgroup to handle concurrency
	wg := &sync.WaitGroup{}

	// scan 1 = run dns templates on scanme.sh
	wg.Add(1)
	go func() {
		defer wg.Done()
		err = ne.ExecuteNucleiWithOpts([]string{"scanme.sh"}, nuclei.WithTemplateFilters(nuclei.TemplateFilters{IDs: []string{"screenshot"}}))
		if err != nil {
			panic(err)
		}
	}()

	// scan 2 = run http templates on honey.scanme.sh
	wg.Add(1)
	go func() {
		defer wg.Done()
		err = ne.ExecuteNucleiWithOpts([]string{"honey.scanme.sh"}, nuclei.WithTemplateFilters(nuclei.TemplateFilters{IDs: []string{"screenshot"}}))
		if err != nil {
			panic(err)
		}
	}()

	// wait for all scans to finish
	wg.Wait()
	defer ne.Close()

Relevant log output

[signal SIGSEGV: segmentation violation code=0x2 addr=0x8 pc=0x1021c5600]

goroutine 5325 [running]:
github.com/projectdiscovery/nuclei/v3/pkg/protocols/headless/engine.(*Browser).UserAgent(...)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/protocols/headless/engine/engine.go:134
github.com/projectdiscovery/nuclei/v3/pkg/protocols/headless.(*Request).ExecuteWithResults(0x1402424d600, 0x0?, 0x14027855b30, 0x14027855da0, 0x14027855e00)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/protocols/headless/request.go:50 +0x90
github.com/projectdiscovery/nuclei/v3/pkg/tmplexec/generic.(*Generic).ExecuteWithResults(0x14027f3bef0, 0x14000afbe00)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/tmplexec/generic/exec.go:61 +0x27c
github.com/projectdiscovery/nuclei/v3/pkg/tmplexec.(*TemplateExecuter).Execute(0x140045fd080, 0x14000afbe00)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/tmplexec/exec.go:212 +0x33c
github.com/projectdiscovery/nuclei/v3/pkg/core.(*Engine).executeTemplateWithTargets.func2.1(0x24cccd0?, 0x40?, 0x14003e2ed40)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/core/executors.go:139 +0x1a4
created by github.com/projectdiscovery/nuclei/v3/pkg/core.(*Engine).executeTemplateWithTargets.func2 in goroutine 5324
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/core/executors.go:115 +0x484
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x8 pc=0x1021c5600]

goroutine 5249 [running]:
github.com/projectdiscovery/nuclei/v3/pkg/protocols/headless/engine.(*Browser).UserAgent(...)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/protocols/headless/engine/engine.go:134
github.com/projectdiscovery/nuclei/v3/pkg/protocols/headless.(*Request).ExecuteWithResults(0x1402424d600, 0x0?, 0x14027efc630, 0x14027efc960, 0x14027efc9c0)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/protocols/headless/request.go:50 +0x90
github.com/projectdiscovery/nuclei/v3/pkg/tmplexec/generic.(*Generic).ExecuteWithResults(0x14027f3bef0, 0x14000c66460)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/tmplexec/generic/exec.go:61 +0x27c
github.com/projectdiscovery/nuclei/v3/pkg/tmplexec.(*TemplateExecuter).Execute(0x140045fd080, 0x14000c66460)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/tmplexec/exec.go:212 +0x33c
github.com/projectdiscovery/nuclei/v3/pkg/core.(*Engine).executeTemplateWithTargets.func2.1(0x25e03c0?, 0x40?, 0x14004678c80)
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/core/executors.go:139 +0x1a4
created by github.com/projectdiscovery/nuclei/v3/pkg/core.(*Engine).executeTemplateWithTargets.func2 in goroutine 5248
        /Users/jeya-12107/go/pkg/mod/github.com/projectdiscovery/nuclei/v3@v3.3.7/pkg/core/executors.go:115 +0x484
exit status 2

Environment

- OS: Mac darwin/arm64
- Nuclei: github.com/projectdiscovery/nuclei/v3 v3.3.7
- Go:  go1.23.1 darwin/arm64

Anything else?

Ref : https://discord.com/channels/695645237418131507/1313145260863393862 (dis