Skip to content

GitLab

Static Application Security Testing (SAST) (FREE)

NOTE: The whitepaper "A Seismic Shift in Application Security" explains how 4 of the top 6 attacks were application based. Download it to learn how to protect your organization.

If you're using GitLab CI/CD, you can analyze your source code for known vulnerabilities using Static Application Security Testing (SAST). GitLab checks the SAST report and compares the found vulnerabilities between the source and target branches.

Details of the vulnerabilities found are included in the merge request. (ULTIMATE)

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

A pipeline consists of multiple jobs, including SAST and DAST scanning. If any job fails to finish for any reason, the security dashboard does not show SAST scanner output. For example, if the SAST job finishes but the DAST job fails, the security dashboard does not show SAST results. On failure, the analyzer outputs an exit code.

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.

WARNING: Our SAST jobs require a Linux container type. Windows containers are not yet supported.

WARNING: 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

GitLab SAST supports a variety of languages, package managers, and frameworks. Our SAST security scanners also feature automatic language detection which works even for mixed-language projects. If any supported language is detected in project source code we automatically run the appropriate SAST analyzers.

You can also view our language roadmap and request other language support by opening an issue.

Language (package managers) / framework Scan tool Introduced in GitLab Version
.NET Core Security Code Scan 11.0
.NET Framework Security Code Scan 13.0
Apex (Salesforce) PMD 12.1
C/C++ Flawfinder 10.7
Elixir (Phoenix) Sobelow 11.1
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)
Helm Charts Kubesec 13.1
Java (Ant, Gradle, Maven, and SBT) SpotBugs with the find-sec-bugs plugin 10.6 (Maven), 10.8 (Gradle) & 11.9 (Ant, SBT)
Java (Android) MobSF (beta) 13.5
JavaScript ESLint security plugin 11.8
JavaScript Semgrep 13.10
Kotlin (Android) MobSF (beta) 13.5
Kotlin (General) SpotBugs with the find-sec-bugs plugin 13.11
Kubernetes manifests Kubesec 12.6
Node.js NodeJsScan 11.1
Objective-C (iOS) MobSF (beta) 13.5
PHP phpcs-security-audit 10.8
Python (pip) bandit 10.3
Python Semgrep 13.9
React ESLint react plugin 12.5
React Semgrep 13.10
Ruby brakeman 13.9
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)
Swift (iOS) MobSF (beta) 13.5
TypeScript ESLint security plugin 11.9, merged with ESLint in 13.2
TypeScript Semgrep 13.10

Note that the Java analyzers can also be used for variants like the Gradle wrapper, Grails, and the Maven wrapper.

Multi-project support

Introduced in GitLab 13.7.

GitLab SAST can scan repositories that contain multiple projects.

The following analyzers have multi-project support:

  • Bandit
  • ESLint
  • Gosec
  • Kubesec
  • NodeJsScan
  • MobSF
  • PMD
  • Security Code Scan
  • Semgrep
  • SpotBugs
  • Sobelow

Enable multi-project support for Security Code Scan

Multi-project support in the Security Code Scan requires a Solution (.sln) file in the root of the repository. For details on the Solution format, see the Microsoft reference Solution (.sln) file.

Making SAST analyzers available to all GitLab tiers

All open source (OSS) analyzers have been moved to the GitLab Free tier as of GitLab 13.3.

Summary of features per tier

Different features are available in different GitLab tiers, as shown in the following table:

Capability In Free In Ultimate
Configure SAST Scanners {check-circle} {check-circle}
Customize SAST Settings {check-circle} {check-circle}
View JSON Report {check-circle} {check-circle}
Presentation of JSON Report in Merge Request {dotted-circle} {check-circle}
Address vulnerabilities {dotted-circle} {check-circle}
Access to Security Dashboard {dotted-circle} {check-circle}
Configure SAST in the UI {dotted-circle} {check-circle}
Customize SAST Rulesets {dotted-circle} {check-circle}

Contribute your scanner

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

Configuration

To configure SAST for a project you can:

Configure SAST manually

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: Security/SAST.gitlab-ci.yml

The included template creates SAST jobs in your CI/CD pipeline and scans your project's source code for possible vulnerabilities.

The results are 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.

Configure SAST in the UI (ULTIMATE)

You can enable and configure SAST with a basic configuration using the SAST Configuration page:

  1. From the project's home page, go to Security & Compliance > Configuration in the left sidebar.

  2. If the project does not have a .gitlab-ci.yml file, click Enable in the Static Application Security Testing (SAST) row, otherwise click Configure.

  3. Enter the custom SAST values.

    Custom values are stored in the .gitlab-ci.yml file. For CI/CD variables not in the SAST Configuration page, their values are left unchanged. Default values are inherited from the GitLab SAST template.

  4. Optionally, expand the SAST analyzers section, select individual SAST analyzers and enter custom analyzer values.

  5. Click Create Merge Request.

  6. Review and merge the merge request.

Customizing the SAST settings

The SAST settings can be changed through CI/CD 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: Security/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

WARNING: 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: Security/SAST.gitlab-ci.yml

spotbugs-sast:
  variables:
    FAIL_NEVER: 1

Customize rulesets (ULTIMATE)

Introduced in GitLab 13.5.

You can customize the default scanning rules provided by our SAST analyzers.

Ruleset customization supports two capabilities:

  1. Disabling predefined rules (available for all analyzers).
  2. Modifying the default behavior of a given analyzer (only available for nodejs-scan and gosec).

These capabilities can be used simultaneously.

To customize the default scanning rules, create a file containing custom rules. These rules are passed through to the analyzer's underlying scanner tools.

To create a custom ruleset:

  1. Create a .gitlab directory at the root of your project, if one doesn't already exist.

  2. Create a custom ruleset file named sast-ruleset.toml in the .gitlab directory.

  3. In the sast-ruleset.toml file, do one of the following:

    • Disable predefined rules belonging to SAST analyzers. In this example, the three disabled rules belong to eslint and sobelow by matching the corresponding identifiers' type and value:

      [eslint]
  [[eslint.ruleset]]
    disable = true
    [eslint.ruleset.identifier]
      type = "eslint_rule_id"
      value = "security/detect-object-injection"

  [[eslint.ruleset]]
    disable = true
    [eslint.ruleset.identifier]
      type = "cwe"
      value = "185"

[sobelow]
  [[sobelow.ruleset]]
    disable = true
    [sobelow.ruleset.identifier]
      type = "sobelow_rule_id"
      value = "sql_injection"

    • Define a custom analyzer configuration. In this example, customized rules are defined for the nodejs-scan scanner:

      [nodejs-scan]
  description = 'custom ruleset for nodejs-scan'

  [[nodejs-scan.passthrough]]
    type  = "raw"
    value = '''
- nodejs-extensions:
  - .js

  template-extensions:
  - .new
  - .hbs
  - ''

  ignore-filenames:
- skip.js

  ignore-paths:
  - __MACOSX
  - skip_dir
  - node_modules

  ignore-extensions:
  - .hbs

  ignore-rules:
  - regex_injection_dos
  - pug_jade_template
  - express_xss

'''

    • Provide the name of the file containing a custom analyzer configuration. In this example, customized rules for the gosec scanner are contained in the file gosec-config.json:

      [gosec]
  description = 'custom ruleset for gosec'

  [[gosec.passthrough]]
    type  = "file"
    value = "gosec-config.json"

Using CI/CD 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 CI/CD variables.

Using a CI/CD 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 CI/CD variable.

Read more on how to use private Maven repositories.

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: Security/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 in 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 CI/CD variable can be provided to the analyzer and compilation is skipped:

stages:
  - build
  - test

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

build:
  image: maven:3.6-jdk-8-slim
  stage: build
  script:
    - mvn package -Dmaven.repo.local=./.m2/repository
  artifacts:
    paths:
      - .m2/
      - target/

spotbugs-sast:
  dependencies:
    - build
  variables:
    MAVEN_REPO_PATH: ./.m2/repository
    COMPILE: "false"
  artifacts:
    reports:
      sast: gl-sast-report.json

To allow the analyzer to recognize the compiled artifacts, you must explicitly specify the path to the vendored directory. This configuration can vary per analyzer but in the case of Java above, you can use MAVEN_REPO_PATH. See Analyzer settings for the complete list of available options.

Available variables

SAST can be configured using CI/CD variables.

Logging level

Introduced in GitLab 13.1.

To control the verbosity of logs, set the SECURE_LOG_LEVEL environment variable. Messages of this logging level or higher are output.

From highest to lowest severity, the logging levels are:

  • fatal
  • error
  • warn
  • info (default)
  • debug

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 in the SAST environment. The ADDITIONAL_CA_CERT_BUNDLE value should contain the text representation of the X.509 PEM public-key certificate. For example, to configure this value in the .gitlab-ci.yml file, use the following:

variables:
  ADDITIONAL_CA_CERT_BUNDLE: |
      -----BEGIN CERTIFICATE-----
      MIIGqTCCBJGgAwIBAgIQI7AVxxVwg2kch4d56XNdDjANBgkqhkiG9w0BAQsFADCB
      ...
      jWgmPqF3vUbZE0EyScetPJquRFRKIesyJuBFMAs=
      -----END CERTIFICATE-----

The ADDITIONAL_CA_CERT_BUNDLE value can also be configured as a custom variable in the UI, either as a file, which requires the path to the certificate, or as a variable, which requires the text representation of the certificate.

Docker images

The following are Docker image-related CI/CD variables.

CI/CD 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_TAG DEPRECATED: Override the Docker tag of the default images. Read more about customizing analyzers.
SAST_DEFAULT_ANALYZERS DEPRECATED: Override the names of default images. Scheduled for removal in GitLab 14.0.
SAST_EXCLUDED_ANALYZERS Names of default images that should never run. Read more about customizing analyzers.

Vulnerability filters

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

CI/CD variable Default value Description
SAST_EXCLUDED_PATHS spec, test, tests, tmp 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 also match patterns. You might need to exclude temporary directories used by your build tool as these can generate false positives. To exclude paths, copy and paste the default excluded paths, then add your own paths to be excluded. If you don't specify the default excluded paths, you will override the defaults and only paths you specify will be excluded from the SAST scans.
SEARCH_MAX_DEPTH 4 SAST searches the repository to detect the programming languages used, and selects the matching analyzers. Set the value of SEARCH_MAX_DEPTH to specify how many directory levels the search phase should span. After the analyzers have been selected, the entire repository is analyzed.
SAST_BANDIT_EXCLUDED_PATHS Comma-separated list of paths to exclude from scan. Uses Python's fnmatch syntax; For example: '*/tests/*, */venv/*'
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_GOSEC_LEVEL 0 Ignore Gosec vulnerabilities under given confidence level. Integer, 0=Undefined, 1=Low, 2=Medium, 3=High.

Analyzer settings

Some analyzers can be customized with CI/CD variables.

CI/CD variable Analyzer Description
SCAN_KUBERNETES_MANIFESTS Kubesec Set to "true" to scan Kubernetes manifests.
KUBESEC_HELM_CHARTS_PATH Kubesec Optional path to Helm charts that helm uses to generate a Kubernetes manifest that kubesec scans. If dependencies are defined, helm dependency build should be ran in a before_script to fetch the necessary dependencies.
KUBESEC_HELM_OPTIONS Kubesec Additional arguments for the helm executable.
COMPILE SpotBugs Set to false to disable project compilation and dependency fetching. Introduced in GitLab 13.1.
ANT_HOME SpotBugs The ANT_HOME 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.
SAST_DISABLE_BABEL NodeJsScan Disable Babel processing for the NodeJsScan scanner. Set to true to disable Babel processing. Introduced in GitLab 13.2.

Custom CI/CD variables

Introduced in GitLab Ultimate 12.5.

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

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

Experimental features

You can receive early access to experimental features. Experimental features might be added, removed, or promoted to regular features at any time.

Experimental features available are:

Enable experimental features

To enable experimental features, add the following to your .gitlab-ci.yml file:

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

variables:
  SAST_EXPERIMENTAL_FEATURES: "true"

Reports JSON format

The SAST tool emits a JSON report file. For more information, see the schema for this report.

The JSON report file can be downloaded from the CI pipelines page, or the pipelines tab on merge requests by setting artifacts: paths to gl-sast-report.json. For more information see Downloading artifacts.

Here's an example SAST report:

{
  "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": []
}

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:

  • GitLab Runner with the docker or kubernetes executor.
  • A Docker Container Registry with locally available copies of SAST analyzer images.
  • Configure certificate checking of packages (optional).

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. The GitLab Runner 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/security-code-scan:2
registry.gitlab.com/gitlab-org/security-products/analyzers/semgrep:2
registry.gitlab.com/gitlab-org/security-products/analyzers/sobelow:2
registry.gitlab.com/gitlab-org/security-products/analyzers/spotbugs: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. These scanners are periodically updated with new definitions, and you may be able to make occasional updates on your own.

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.

If support for Custom Certificate Authorities are needed

Support for custom certificate authorities was introduced in the following versions.

Analyzer Version
bandit v2.3.0
brakeman v2.1.0
eslint v2.9.2
flawfinder v2.3.0
gosec v2.5.0
kubesec v2.1.0
nodejs-scan v2.9.5
phpcs-security-audit v2.8.2
pmd-apex v2.1.0
security-code-scan v2.7.3
semgrep v0.0.1
sobelow v2.2.0
spotbugs v2.7.1

Set SAST CI/CD variables to use local SAST analyzers

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

include:
  - template: Security/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.

Configure certificate checking of packages

If a SAST job invokes a package manager, you must configure its certificate verification. In an offline environment, certificate verification with an external source is not possible. Either use a self-signed certificate or disable certificate verification. Refer to the package manager's documentation for instructions.

Running SAST in SELinux

By default SAST analyzers are supported in GitLab instances hosted on SELinux. Adding a before_script in an overridden SAST job may not work as runners hosted on SELinux have restricted permissions.

Troubleshooting

SAST debug logging

Increase the Secure scanner log verbosity to debug in a global CI variable to help troubleshoot SAST jobs.

variables:
  SECURE_LOG_LEVEL: "debug"

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.

Getting warning message gl-sast-report.json: no matching files

For information on this, see the general Application Security troubleshooting section.

Error: sast is used for configuration only, and its script should not be executed

For information on this, see the GitLab Secure troubleshooting section.

Limitation when using rules:exists

The SAST CI template uses the rules:exists parameter. For performance reasons, a maximum number of matches are made against the given glob pattern. If the number of matches exceeds the maximum, the rules:exists parameter returns true. Depending on the number of files in your repository, a SAST job might be triggered even if the scanner doesn't support your project. For more details about this issue, see the rules:exists documentation.

SpotBugs UTF-8 unmappable character errors

These errors occur when UTF-8 encoding isn't enabled on a SpotBugs build and there are UTF-8 characters in the source code. To fix this error, enable UTF-8 for your project's build tool.

For Gradle builds, add the following to your build.gradle file:

compileJava.options.encoding = 'UTF-8'
tasks.withType(JavaCompile) {
    options.encoding = 'UTF-8'
}

For Maven builds, add the following to your pom.xml file:

<properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

Flawfinder encoding error

This occurs when Flawfinder encounters an invalid UTF-8 character. To fix this, convert all source code in your project to UTF-8 character encoding. This can be done with cvt2utf or iconv either over the entire project or per job using the before_script feature.