Static Application Security Testing (SAST)

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Overview

If you’re using GitLab CI/CD, you can analyze your source code for known vulnerabilities using Static Application Security Testing (SAST).

You can take advantage of SAST by doing one of the following:

GitLab checks the SAST report, compares the found vulnerabilities between the source and target branches, and shows the information right on the merge request.

SAST Widget

The results are sorted by the priority of the vulnerability:

  1. Critical
  2. High
  3. Medium
  4. Low
  5. Unknown
  6. Everything else
Note: A pipeline consists of multiple jobs, including SAST and DAST scanning. If any job fails to finish for any reason, the security dashboard won’t show SAST scanner output. For example, if the SAST job finishes but the DAST job fails, the security dashboard won’t show SAST results. The analyzer will output an exit code on failure.

Use cases

  • Your code has a potentially dangerous attribute in a class, or unsafe code that can lead to unintended code execution.
  • Your application is vulnerable to cross-site scripting (XSS) attacks that can be leveraged to unauthorized access to session data.

Requirements

To run SAST jobs, by default, you need GitLab Runner with the docker or kubernetes executor. If you’re using the shared Runners on GitLab.com, this is enabled by default.

Beginning with GitLab 13.0, Docker privileged mode is necessary only if you’ve enabled Docker-in-Docker for SAST.

Caution: Our SAST jobs currently expect a Linux container type. Windows containers are not yet supported.
Caution: If you use your own Runners, make sure the Docker version installed is not 19.03.0. See troubleshooting information for details.

Supported languages and frameworks

The following table shows which languages, package managers and frameworks are supported and which tools are used.

Language (package managers) / framework Scan tool Introduced in GitLab Version
.NET Core Security Code Scan 11.0
.NET Framework Security Code Scan 13.0
Any Gitleaks and TruffleHog 11.9
Apex (Salesforce) PMD 12.1
C/C++ Flawfinder 10.7
Elixir (Phoenix) Sobelow 11.10
Go Gosec 10.7
Groovy (Ant, Gradle, Maven and SBT) SpotBugs with the find-sec-bugs plugin 11.3 (Gradle) & 11.9 (Ant, Maven, SBT)
Java (Ant, Gradle, Maven and SBT) SpotBugs with the find-sec-bugs plugin 10.6 (Maven), 10.8 (Gradle) & 11.9 (Ant, SBT)
JavaScript ESLint security plugin 11.8
Kubernetes manifests Kubesec 12.6
Node.js NodeJsScan 11.1
PHP phpcs-security-audit 10.8
Python (pip) bandit 10.3
React ESLint react plugin 12.5
Ruby on Rails brakeman 10.3
Scala (Ant, Gradle, Maven and SBT) SpotBugs with the find-sec-bugs plugin 11.0 (SBT) & 11.9 (Ant, Gradle, Maven)
TypeScript tslint-config-security 11.9
Note: The Java analyzers can also be used for variants like the Gradle wrapper, Grails and the Maven wrapper.

Contribute your scanner

The Security Scanner Integration documentation explains how to integrate other security scanners into GitLab.

Configuration

Note: You don’t have to configure SAST manually as shown in this section if you’re using Auto SAST provided by Auto DevOps.

For GitLab 11.9 and later, to enable SAST you must include the SAST.gitlab-ci.yml template provided as a part of your GitLab installation. For GitLab versions earlier than 11.9, you can copy and use the job as defined that template.

Add the following to your .gitlab-ci.yml file:

include:
  - template: SAST.gitlab-ci.yml

The included template will create SAST jobs in your CI/CD pipeline and scan your project’s source code for possible vulnerabilities.

The results will be saved as a SAST report artifact that you can later download and analyze. Due to implementation limitations, we always take the latest SAST artifact available.

Customizing the SAST settings

The SAST settings can be changed through environment variables by using the variables parameter in .gitlab-ci.yml. In the following example, we include the SAST template and at the same time we set the SAST_GOSEC_LEVEL variable to 2:

include:
  - template: SAST.gitlab-ci.yml

variables:
  SAST_GOSEC_LEVEL: 2

Because the template is evaluated before the pipeline configuration, the last mention of the variable takes precedence.

Overriding SAST jobs

Deprecation: Beginning in GitLab 13.0, the use of only and except is no longer supported. When overriding the template, you must use rules instead.

To override a job definition, (for example, change properties like variables or dependencies), declare a job with the same name as the SAST job to override. Place this new job after the template inclusion and specify any additional keys under it. For example, this enables FAIL_NEVER for the spotbugs analyzer:

include:
  - template: SAST.gitlab-ci.yml

spotbugs-sast:
  variables:
    FAIL_NEVER: 1

Using environment variables to pass credentials for private repositories

Some analyzers require downloading the project’s dependencies in order to perform the analysis. In turn, such dependencies may live in private Git repositories and thus require credentials like username and password to download them. Depending on the analyzer, such credentials can be provided to it via custom environment variables.

Using a variable to pass username and password to a private Maven repository

If your private Maven repository requires login credentials, you can use the MAVEN_CLI_OPTS environment variable.

Read more on how to use private Maven repositories.

Enabling Docker-in-Docker

If needed, you can enable Docker-in-Docker to restore the SAST behavior that existed prior to GitLab 13.0. Follow these steps to do so:

  1. Configure GitLab Runner with Docker-inDocker in privileged mode.
  2. Set the variable SAST_DISABLE_DIND set to false:

    include:
      - template: SAST.gitlab-ci.yml
    
    variables:
      SAST_DISABLE_DIND: "false"
    

This creates a single sast job in your CI/CD pipeline instead of multiple <analyzer-name>-sast jobs.

Enabling Kubesec analyzer

Introduced in GitLab Ultimate 12.6.

You need to set SCAN_KUBERNETES_MANIFESTS to "true" to enable the Kubesec analyzer. In .gitlab-ci.yml, define:

include:
  - template: SAST.gitlab-ci.yml

variables:
  SCAN_KUBERNETES_MANIFESTS: "true"

Pre-compilation

If your project requires custom build configurations, it can be preferable to avoid compilation during your SAST execution and instead pass all job artifacts from an earlier stage within the pipeline. This is the current strategy when requiring a before_script execution to prepare your scan job.

To pass your project’s dependencies as artifacts, the dependencies must be included in the project’s working directory and specified using the artifacts:path configuration. If all dependencies are present, the -compile=false flag can be provided to the analyzer and compilation will be skipped:

image: maven:3.6-jdk-8-alpine

stages:
 - build
 - test

include:
  - template: SAST.gitlab-ci.yml

build:
  stage: build
  script:
    - mvn package -Dmaven.repo.local=./.m2/repository
  artifacts:
    paths:
      - .m2/
      - target/

spotbugs-sast:
  dependencies:
    - build
  script:
    - /analyzer run -compile=false
  variables:
    MAVEN_REPO_PATH: ./.m2/repository
  artifacts:
    reports:
      sast: gl-sast-report.json
Note: The path to the vendored directory must be specified explicitly to allow the analyzer to recognize the compiled artifacts. This configuration can vary per analyzer but in the case of Java above, MAVEN_REPO_PATH can be used. See Analyzer settings for the complete list of available options.

Available variables

SAST can be configured using environment variables.

Custom Certificate Authority

To trust a custom Certificate Authority, set the ADDITIONAL_CA_CERT_BUNDLE variable to the bundle of CA certs that you want to trust within the SAST environment.

Docker images

The following are Docker image-related variables.

Environment variable Description
SECURE_ANALYZERS_PREFIX Override the name of the Docker registry providing the default images (proxy). Read more about customizing analyzers.
SAST_ANALYZER_IMAGE_PREFIX DEPRECATED: Use SECURE_ANALYZERS_PREFIX instead.
SAST_ANALYZER_IMAGE_TAG DEPRECATED: Override the Docker tag of the default images. Read more about customizing analyzers.
SAST_DEFAULT_ANALYZERS Override the names of default images. Read more about customizing analyzers.
SAST_DISABLE_DIND Disable Docker-in-Docker and run analyzers individually. This variable is true by default.

Vulnerability filters

Some analyzers make it possible to filter out vulnerabilities under a given threshold.

Environment variable Default value Description
SAST_EXCLUDED_PATHS - Exclude vulnerabilities from output based on the paths. This is a comma-separated list of patterns. Patterns can be globs, or file or folder paths (for example, doc,spec ). Parent directories will also match patterns.
SAST_BANDIT_EXCLUDED_PATHS - comma-separated list of paths to exclude from scan. Uses Python’s fnmatch syntax
SAST_BRAKEMAN_LEVEL 1 Ignore Brakeman vulnerabilities under given confidence level. Integer, 1=Low 3=High.
SAST_FLAWFINDER_LEVEL 1 Ignore Flawfinder vulnerabilities under given risk level. Integer, 0=No risk, 5=High risk.
SAST_GITLEAKS_ENTROPY_LEVEL 8.0 Minimum entropy for secret detection. Float, 0.0 = low, 8.0 = high.
SAST_GOSEC_LEVEL 0 Ignore Gosec vulnerabilities under given confidence level. Integer, 0=Undefined, 1=Low, 2=Medium, 3=High.
SAST_GITLEAKS_COMMIT_FROM - The commit a Gitleaks scan starts at.
SAST_GITLEAKS_COMMIT_TO - The commit a Gitleaks scan ends at.
SAST_GITLEAKS_HISTORIC_SCAN false Flag to enable a historic Gitleaks scan.

Docker-in-Docker orchestrator

The following variables configure the Docker-in-Docker orchestrator, and therefore are only used when the Docker-in-Docker mode is enabled.

Environment variable Default value Description
SAST_ANALYZER_IMAGES   Comma-separated list of custom images. Default images are still enabled. Read more about customizing analyzers.
SAST_PULL_ANALYZER_IMAGES 1 Pull the images from the Docker registry (set to 0 to disable). Read more about customizing analyzers.
SAST_DOCKER_CLIENT_NEGOTIATION_TIMEOUT 2m Time limit for Docker client negotiation. Timeouts are parsed using Go’s ParseDuration. Valid time units are ns, us (or µs), ms, s, m, h. For example, 300ms, 1.5h or 2h45m.
SAST_PULL_ANALYZER_IMAGE_TIMEOUT 5m Time limit when pulling the image of an analyzer. Timeouts are parsed using Go’s ParseDuration. Valid time units are ns, us (or µs), ms, s, m, h. For example, 300ms, 1.5h or 2h45m.
SAST_RUN_ANALYZER_TIMEOUT 20m Time limit when running an analyzer. Timeouts are parsed using Go’s ParseDuration. Valid time units are ns, us (or µs), ms, s, m, h. For example, 300ms, 1.5h or 2h45m.

Analyzer settings

Some analyzers can be customized with environment variables.

Environment variable Analyzer Description
SCAN_KUBERNETES_MANIFESTS Kubesec Set to "true" to scan Kubernetes manifests.
ANT_HOME SpotBugs The ANT_HOME environment variable.
ANT_PATH SpotBugs Path to the ant executable.
GRADLE_PATH SpotBugs Path to the gradle executable.
JAVA_OPTS SpotBugs Additional arguments for the java executable.
JAVA_PATH SpotBugs Path to the java executable.
SAST_JAVA_VERSION SpotBugs Which Java version to use. Supported versions are 8 and 11. Defaults to 8.
MAVEN_CLI_OPTS SpotBugs Additional arguments for the mvn or mvnw executable.
MAVEN_PATH SpotBugs Path to the mvn executable.
MAVEN_REPO_PATH SpotBugs Path to the Maven local repository (shortcut for the maven.repo.local property).
SBT_PATH SpotBugs Path to the sbt executable.
FAIL_NEVER SpotBugs Set to 1 to ignore compilation failure.
SAST_GOSEC_CONFIG Gosec Path to configuration for Gosec (optional).
PHPCS_SECURITY_AUDIT_PHP_EXTENSIONS phpcs-security-audit Comma separated list of additional PHP Extensions.

Custom environment variables

Introduced in GitLab Ultimate 12.5.

In addition to the aforementioned SAST configuration variables, all custom environment variables are propagated to the underlying SAST analyzer images if the SAST vendored template is used.

Caution: Variables having names starting with these prefixes will not be propagated to the SAST Docker container and/or analyzer containers: DOCKER_, CI, GITLAB_, FF_, HOME, PWD, OLDPWD, PATH, SHLVL, HOSTNAME.

Reports JSON format

Caution: The JSON report artifacts are not a public API of SAST and their format may change in the future.

The SAST tool emits a JSON report file. Here is an example of the report structure with all important parts of it highlighted:

{
  "version": "2.0",
  "vulnerabilities": [
    {
      "id": "9e96e0ab-23da-4d7d-a09e-0acbaa5e83ca",
      "category": "sast",
      "name": "Predictable pseudorandom number generator",
      "message": "Predictable pseudorandom number generator",
      "description": "The use of java.util.Random is predictable",
      "severity": "Medium",
      "confidence": "Medium",
      "scanner": {
        "id": "find_sec_bugs",
        "name": "Find Security Bugs"
      },
      "location": {
        "file": "groovy/src/main/groovy/com/gitlab/security_products/tests/App.groovy",
        "start_line": 47,
        "end_line": 47,
        "class": "com.gitlab.security_products.tests.App",
        "method": "generateSecretToken2",
        "dependency": {
          "package": {}
        }
      },
      "identifiers": [
        {
          "type": "find_sec_bugs_type",
          "name": "Find Security Bugs-PREDICTABLE_RANDOM",
          "value": "PREDICTABLE_RANDOM",
          "url": "https://find-sec-bugs.github.io/bugs.htm#PREDICTABLE_RANDOM"
        },
        {
          "type": "cwe",
          "name": "CWE-330",
          "value": "330",
          "url": "https://cwe.mitre.org/data/definitions/330.html"
        }
      ]
    },
    {
      "id": "e6dbf91f-4c07-46f7-a365-0169489c27d1",
      "category": "sast",
      "message": "Probable insecure usage of temp file/directory.",
      "severity": "Medium",
      "confidence": "Medium",
      "scanner": {
        "id": "bandit",
        "name": "Bandit"
      },
      "location": {
        "file": "python/hardcoded/hardcoded-tmp.py",
        "start_line": 10,
        "end_line": 10,
        "dependency": {
          "package": {}
        }
      },
      "identifiers": [
        {
          "type": "bandit_test_id",
          "name": "Bandit Test ID B108",
          "value": "B108",
          "url": "https://docs.openstack.org/bandit/latest/plugins/b108_hardcoded_tmp_directory.html"
        }
      ]
    },
  ],
  "remediations": []
}
Deprecation: Beginning with GitLab 12.9, SAST no longer reports undefined severity and confidence levels.

Here is the description of the report file structure nodes and their meaning. All fields are mandatory in the report JSON unless stated otherwise. Presence of optional fields depends on the underlying analyzers being used.

Report JSON node Function
version Report syntax version used to generate this JSON.
vulnerabilities Array of vulnerability objects.
vulnerabilities[].id Unique identifier of the vulnerability.
vulnerabilities[].category Where this vulnerability belongs (such as SAST, Dependency Scanning). For SAST, it will always be sast.
vulnerabilities[].name Name of the vulnerability. Must not include the occurrence’s specific information. Optional.
vulnerabilities[].message A short text that describes the vulnerability, it may include the occurrence’s specific information. Optional.
vulnerabilities[].description A long text that describes the vulnerability. Optional.
vulnerabilities[].cve (DEPRECATED - use vulnerabilities[].id instead) A fingerprint string value that represents a concrete occurrence of the vulnerability. It’s used to determine whether two vulnerability occurrences are same or different. May not be 100% accurate. This is NOT a CVE.
vulnerabilities[].severity How much the vulnerability impacts the software. Possible values: Info, Unknown, Low, Medium, High, Critical.
vulnerabilities[].confidence How reliable the vulnerability’s assessment is. Possible values: Ignore, Unknown, Experimental, Low, Medium, High, Confirmed.
vulnerabilities[].solution Explanation of how to fix the vulnerability. Optional.
vulnerabilities[].scanner A node that describes the analyzer used to find this vulnerability.
vulnerabilities[].scanner.id ID of the scanner as a snake_case string.
vulnerabilities[].scanner.name Name of the scanner, for display purposes.
vulnerabilities[].location A node that tells where the vulnerability is located.
vulnerabilities[].location.file Path to the file where the vulnerability is located. Optional.
vulnerabilities[].location.start_line The first line of the code affected by the vulnerability. Optional.
vulnerabilities[].location.end_line The last line of the code affected by the vulnerability. Optional.
vulnerabilities[].location.class If specified, provides the name of the class where the vulnerability is located. Optional.
vulnerabilities[].location.method If specified, provides the name of the method where the vulnerability is located. Optional.
vulnerabilities[].identifiers An ordered array of references that identify a vulnerability on internal or external databases.
vulnerabilities[].identifiers[].type Type of the identifier. Possible values: common identifier types (among cve, cwe, osvdb, and usn) or analyzer-dependent ones (like bandit_test_id for Bandit analyzer).
vulnerabilities[].identifiers[].name Name of the identifier for display purposes.
vulnerabilities[].identifiers[].value Value of the identifier for matching purposes.
vulnerabilities[].identifiers[].url URL to identifier’s documentation. Optional.

Secret detection

Learn more about Secret Detection.

Security Dashboard

The Security Dashboard is a good place to get an overview of all the security vulnerabilities in your groups, projects and pipelines. Read more about the Security Dashboard.

Interacting with the vulnerabilities

Once a vulnerability is found, you can interact with it. Read more on how to interact with the vulnerabilities.

Vulnerabilities database

Vulnerabilities contained within the vulnerability database can be searched and viewed at the GitLab vulnerability advisory database.

Vulnerabilities database update

For more information about the vulnerabilities database update, check the maintenance table.

Running SAST in an offline environment

For self-managed GitLab instances in an environment with limited, restricted, or intermittent access to external resources through the internet, some adjustments are required for the SAST job to run successfully. For more information, see Offline environments.

Requirements for offline SAST

To use SAST in an offline environment, you need:

Note: GitLab Runner has a default pull policy of always, meaning the Runner tries to pull Docker images from the GitLab container registry even if a local copy is available. GitLab Runner’s pull_policy can be set to if-not-present in an offline environment if you prefer using only locally available Docker images. However, we recommend keeping the pull policy setting to always if not in an offline environment, as this enables the use of updated scanners in your CI/CD pipelines.

Make GitLab SAST analyzer images available inside your Docker registry

For SAST with all supported languages and frameworks, import the following default SAST analyzer images from registry.gitlab.com into your local Docker container registry:

registry.gitlab.com/gitlab-org/security-products/analyzers/bandit:2
registry.gitlab.com/gitlab-org/security-products/analyzers/brakeman:2
registry.gitlab.com/gitlab-org/security-products/analyzers/eslint:2
registry.gitlab.com/gitlab-org/security-products/analyzers/flawfinder:2
registry.gitlab.com/gitlab-org/security-products/analyzers/gosec:2
registry.gitlab.com/gitlab-org/security-products/analyzers/kubesec:2
registry.gitlab.com/gitlab-org/security-products/analyzers/nodejs-scan:2
registry.gitlab.com/gitlab-org/security-products/analyzers/phpcs-security-audit:2
registry.gitlab.com/gitlab-org/security-products/analyzers/pmd-apex:2
registry.gitlab.com/gitlab-org/security-products/analyzers/secrets:2
registry.gitlab.com/gitlab-org/security-products/analyzers/security-code-scan:2
registry.gitlab.com/gitlab-org/security-products/analyzers/sobelow:2
registry.gitlab.com/gitlab-org/security-products/analyzers/spotbugs:2
registry.gitlab.com/gitlab-org/security-products/analyzers/tslint:2

The process for importing Docker images into a local offline Docker registry depends on your network security policy. Please consult your IT staff to find an accepted and approved process by which external resources can be imported or temporarily accessed. Note that these scanners are updated periodically with new definitions, so consider if you’re able to make periodic updates yourself.

For details on saving and transporting Docker images as a file, see Docker’s documentation on docker save, docker load, docker export, and docker import.

Set SAST CI job variables to use local SAST analyzers

Add the following configuration to your .gitlab-ci.yml file. You must replace SAST_ANALYZER_IMAGE_PREFIX to refer to your local Docker container registry:

include:
  - template: SAST.gitlab-ci.yml

variables:
  SECURE_ANALYZERS_PREFIX: "localhost:5000/analyzers"

The SAST job should now use local copies of the SAST analyzers to scan your code and generate security reports without requiring internet access.

Troubleshooting

Error response from daemon: error processing tar file: docker-tar: relocation error

This error occurs when the Docker version that runs the SAST job is 19.03.0. Consider updating to Docker 19.03.1 or greater. Older versions are not affected. Read more in this issue.