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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.enabledbooltrueEnables or disables the installation of the default cascading rules for this scanner
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.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.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.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.

Examples

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"