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Nuclei

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What is Nuclei​

Nuclei is used to send requests across targets based on a template leading to zero false positives and providing fast scanning on large number of hosts. Nuclei offers scanning for a variety of protocols including TCP, DNS, HTTP, File, etc. With powerful and flexible templating, all kinds of security checks can be modelled with Nuclei.

To learn more about the Nuclei scanner itself visit Nuclei GitHub or Nuclei Website.

Deployment​

The nuclei chart can be deployed via helm:

# Install HelmChart (use -n to configure another namespace)
helm upgrade --install nuclei secureCodeBox/nuclei

Scanner Configuration​

The following security scan configuration example are based on the Nuclei Documentation, please take a look at the original documentation for more configuration examples.

nuclei -h
Nuclei is a fast, template based vulnerability scanner focusing
on extensive configurability, massive extensibility and ease of use.

Usage:
  nuclei [flags]

Flags:
TARGET:
   -u, -target string[]  target URLs/hosts to scan
   -l, -list string      path to file containing a list of target URLs/hosts to scan (one per line)

TEMPLATES:
   -tl                      list all available templates
   -t, -templates string[]  template or template directory paths to include in the scan
   -w, -workflows string[]  list of workflows to run
   -nt, -new-templates      run newly added templates only
   -validate                validate the passed templates to nuclei

FILTERING:
   -tags string[]                         execute a subset of templates that contain the provided tags
   -include-tags string[]                 tags from the default deny list that permit executing more intrusive templates
   -etags, -exclude-tags string[]         exclude templates with the provided tags
   -include-templates string[]            templates to be executed even if they are excluded either by default or configuration
   -exclude-templates, -exclude string[]  template or template directory paths to exclude
   -severity, -impact string[]            execute templates that match the provided severities only
   -author string[]                       execute templates that are (co-)created by the specified authors

OUTPUT:
   -o, -output string            output file to write found issues/vulnerabilities
   -silent                       display findings only
   -v, -verbose                  show verbose output
   -vv                           display extra verbose information
   -nc, -no-color                disable output content coloring (ANSI escape codes)
   -json                         write output in JSONL(ines) format
   -irr, -include-rr             include request/response pairs in the JSONL output (for findings only)
   -nm, -no-meta                 don't display match metadata
   -rdb, -report-db string       local nuclei reporting database (always use this to persist report data)
   -me, -markdown-export string  directory to export results in markdown format
   -se, -sarif-export string     file to export results in SARIF format

CONFIGURATIONS:
   -config string              path to the nuclei configuration file
   -rc, -report-config string  nuclei reporting module configuration file
   -H, -header string[]        custom headers in header:value format
   -V, -var value              custom vars in var=value format
   -r, -resolvers string       file containing resolver list for nuclei
   -system-resolvers           use system DNS resolving as error fallback
   -passive                    enable passive HTTP response processing mode
   -env-vars                   Enable environment variables support

INTERACTSH:
   -no-interactsh                     do not use interactsh server for blind interaction polling
   -interactsh-url string             self-hosted Interactsh Server URL (default "https://interact.sh")
   -interactions-cache-size int       number of requests to keep in the interactions cache (default 5000)
   -interactions-eviction int         number of seconds to wait before evicting requests from cache (default 60)
   -interactions-poll-duration int    number of seconds to wait before each interaction poll request (default 5)
   -interactions-cooldown-period int  extra time for interaction polling before exiting (default 5)

RATE-LIMIT:
   -rl, -rate-limit int          maximum number of requests to send per second (default 150)
   -rlm, -rate-limit-minute int  maximum number of requests to send per minute
   -bs, -bulk-size int           maximum number of hosts to be analyzed in parallel per template (default 25)
   -c, -concurrency int          maximum number of templates to be executed in parallel (default 10)

OPTIMIZATIONS:
   -timeout int               time to wait in seconds before timeout (default 5)
   -retries int               number of times to retry a failed request (default 1)
   -project                   use a project folder to avoid sending same request multiple times
   -project-path string       set a specific project path (default "/var/folders/xq/zxykn5wd0tx796f0xhxf94th0000gp/T/")
   -spm, -stop-at-first-path  stop processing HTTP requests after the first match (may break template/workflow logic)

HEADLESS:
   -headless          enable templates that require headless browser support
   -page-timeout int  seconds to wait for each page in headless mode (default 20)
   -show-browser      show the browser on the screen when running templates with headless mode

DEBUG:
   -debug                     show all requests and responses
   -debug-req                 show all sent requests
   -debug-resp                show all received responses
   -proxy, -proxy-url string  URL of the HTTP proxy server
   -proxy-socks-url string    URL of the SOCKS proxy server
   -trace-log string          file to write sent requests trace log
   -version                   show nuclei version
   -tv, -templates-version    shows the version of the installed nuclei-templates

UPDATE:
   -update                        update nuclei to the latest released version
   -ut, -update-templates         update the community templates to latest released version
   -nut, -no-update-templates     Do not check for nuclei-templates updates
   -ud, -update-directory string  overwrite the default nuclei-templates directory (default "/Users/robert/nuclei-templates")

STATISTICS:
   -stats                    display statistics about the running scan
   -stats-json               write statistics data to an output file in JSONL(ines) format
   -si, -stats-interval int  number of seconds to wait between showing a statistics update (default 5)
   -metrics                  expose nuclei metrics on a port
   -metrics-port int         port to expose nuclei metrics on (default 9092)

Requirements​

Kubernetes: >=v1.11.0-0

Install Nuclei without Template Cache CronJob / PersistentVolume​

Nuclei uses dynamic templates as its scan rules, these determine which requests are performed and which responses are considered to be a finding. These templates are usually dynamically downloaded by nuclei from GitHub before each scan. When you are running dozens of parallel nuclei scans you quickly run into situations where GitHub will rate limit you causing the scans to fail. To avoid these errors we included a CronJob which periodically fetches the current templates and writes them into a kubernetes PersistentVolume (PV). This volume is then mounted (as a ReadOnlyMany mount) into every scan so that nuclei scans have the up-to-date templates without having to download them on every scan.

Unfortunately not every cluster supports the required ReadOnlyMany volume type. In these cases you can disable the template cache mechanism by setting nucleiTemplateCache.enabled=false. Note thought, that this will limit the number of scans you can run in parallel as the rate limit will likely cause some of the scans to fail.

helm install nuclei secureCodeBox/nuclei --set="nucleiTemplateCache.enabled=false"

Values​

KeyTypeDefaultDescription
cascadingRules.enabledboolfalseEnables or disables the installation of the default cascading rules for this scanner
imagePullSecretslist[]Define imagePullSecrets when a private registry is used (see: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/)
nucleiTemplateCache.accessModelist["ReadWriteOnce","ReadOnlyMany"]Depending on your setup you can define the pvc access mode for one ReadWriteOnce or multiple node clusters ReadWriteMany
nucleiTemplateCache.concurrencyPolicystring"Replace"Determines how kubernetes handles cases where multiple instances of the cronjob would work if they are running at the same time. See: https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/#concurrency-policy
nucleiTemplateCache.enabledbooltrueEnables or disables the use of an persistent volume to cache the always downloaded nuclei-templates for all scans.
nucleiTemplateCache.failedJobsHistoryLimitint10Determines how many failed jobs are kept until kubernetes cleans them up. See: https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/#jobs-history-limits
nucleiTemplateCache.schedulestring"0 */1 * * *"The schedule indicates when and how often the nuclei template cache should be updated
nucleiTemplateCache.successfulJobsHistoryLimitint3Determines how many successful jobs are kept until kubernetes cleans them up. See: https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/#jobs-history-limits
parser.affinityobject{}Optional affinity settings that control how the parser job is scheduled (see: https://kubernetes.io/docs/tasks/configure-pod-container/assign-pods-nodes-using-node-affinity/)
parser.envlist[]Optional environment variables mapped into each parseJob (see: https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/)
parser.image.pullPolicystring"IfNotPresent"Image pull policy. One of Always, Never, IfNotPresent. Defaults to Always if :latest tag is specified, or IfNotPresent otherwise. More info: https://kubernetes.io/docs/concepts/containers/images#updating-images
parser.image.repositorystring"docker.io/securecodebox/parser-nuclei"Parser image repository
parser.image.tagstringdefaults to the charts versionParser image tag
parser.resourcesobject{ requests: { cpu: "200m", memory: "100Mi" }, limits: { cpu: "400m", memory: "200Mi" } }Optional resources lets you control resource limits and requests for the parser container. See https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
parser.scopeLimiterAliasesobject{}Optional finding aliases to be used in the scopeLimiter.
parser.tolerationslist[]Optional tolerations settings that control how the parser job is scheduled (see: https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/)
parser.ttlSecondsAfterFinishedstringnilseconds after which the Kubernetes job for the parser will be deleted. Requires the Kubernetes TTLAfterFinished controller: https://kubernetes.io/docs/concepts/workloads/controllers/ttlafterfinished/
scanner.activeDeadlineSecondsstringnilThere are situations where you want to fail a scan Job after some amount of time. To do so, set activeDeadlineSeconds to define an active deadline (in seconds) when considering a scan Job as failed. (see: https://kubernetes.io/docs/concepts/workloads/controllers/job/#job-termination-and-cleanup)
scanner.affinityobject{}Optional affinity settings that control how the scanner job is scheduled (see: https://kubernetes.io/docs/tasks/configure-pod-container/assign-pods-nodes-using-node-affinity/)
scanner.backoffLimitint3There are situations where you want to fail a scan Job after some amount of retries due to a logical error in configuration etc. To do so, set backoffLimit to specify the number of retries before considering a scan Job as failed. (see: https://kubernetes.io/docs/concepts/workloads/controllers/job/#pod-backoff-failure-policy)
scanner.envlist[]Optional environment variables mapped into each scanJob (see: https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/)
scanner.extraContainerslist[]Optional additional Containers started with each scanJob (see: https://kubernetes.io/docs/concepts/workloads/pods/init-containers/)
scanner.extraVolumeMountslist[]Optional VolumeMounts mapped into each scanJob (see: https://kubernetes.io/docs/concepts/storage/volumes/)
scanner.extraVolumeslist[]Optional Volumes mapped into each scanJob (see: https://kubernetes.io/docs/concepts/storage/volumes/)
scanner.image.pullPolicystring"IfNotPresent"Image pull policy. One of Always, Never, IfNotPresent. Defaults to Always if :latest tag is specified, or IfNotPresent otherwise. More info: https://kubernetes.io/docs/concepts/containers/images#updating-images
scanner.image.repositorystring"docker.io/projectdiscovery/nuclei"Container Image to run the scan
scanner.image.tagstringnildefaults to the charts appVersion
scanner.nameAppendstringnilappend a string to the default scantype name.
scanner.podSecurityContextobject{}Optional securityContext set on scanner pod (see: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/)
scanner.resourcesobject{}CPU/memory resource requests/limits (see: https://kubernetes.io/docs/tasks/configure-pod-container/assign-memory-resource/, https://kubernetes.io/docs/tasks/configure-pod-container/assign-cpu-resource/)
scanner.securityContextobject{"allowPrivilegeEscalation":false,"capabilities":{"drop":["all"]},"privileged":false,"readOnlyRootFilesystem":false,"runAsNonRoot":false}Optional securityContext set on scanner container (see: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/)
scanner.securityContext.allowPrivilegeEscalationboolfalseEnsure that users privileges cannot be escalated
scanner.securityContext.capabilities.drop[0]string"all"This drops all linux privileges from the container.
scanner.securityContext.privilegedboolfalseEnsures that the scanner container is not run in privileged mode
scanner.securityContext.readOnlyRootFilesystemboolfalsePrevents write access to the containers file system
scanner.securityContext.runAsNonRootboolfalseEnforces that the scanner image is run as a non root user
scanner.suspendboolfalseif set to true the scan job will be suspended after creation. You can then resume the job using kubectl resume <jobname> or using a job scheduler like kueue
scanner.tolerationslist[]Optional tolerations settings that control how the scanner job is scheduled (see: https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/)
scanner.ttlSecondsAfterFinishedstringnilseconds after which the Kubernetes job for the scanner will be deleted. Requires the Kubernetes TTLAfterFinished controller: https://kubernetes.io/docs/concepts/workloads/controllers/ttlafterfinished/

License​

License

Code of secureCodeBox is licensed under the Apache License 2.0.

CPU architectures​

The scanner is currently supported for these CPU architectures:

  • linux/amd64
  • linux/arm64

Examples​

bodgeit​

# SPDX-FileCopyrightText: the secureCodeBox authors
#
# SPDX-License-Identifier: Apache-2.0

apiVersion: "execution.securecodebox.io/v1"
kind: Scan
metadata:
  name: "nuclei-bodgeit-scan"
spec:
  scanType: "nuclei"
  parameters:
    - "-no-interactsh"
    - "-v"
    - "-debug"
    - "-target"
    - "http://bodgeit.demo-targets.svc.cluster.local:8080"

example.com​

# SPDX-FileCopyrightText: the secureCodeBox authors
#
# SPDX-License-Identifier: Apache-2.0

apiVersion: "execution.securecodebox.io/v1"
kind: Scan
metadata:
  name: "nuclei-example-scan"
spec:
  scanType: "nuclei"
  parameters:
    # Target domain name of the finding and start a nuclei scan
    - "-u"
    - "https://example.com"

secureCodeBox.io​

# SPDX-FileCopyrightText: the secureCodeBox authors
#
# SPDX-License-Identifier: Apache-2.0

apiVersion: "execution.securecodebox.io/v1"
kind: Scan
metadata:
  name: "nuclei-securecodebox-scan"
spec:
  scanType: "nuclei"
  parameters:
    # Target domain name of the finding and start a nuclei scan
    - "-u"
    - "https://www.secureCodeBox.io"