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Stored XSS on the job page

HackerOne report #856554 by mike12 on 2020-04-22:

Hello Gitlab!

Steps to reproduce:

  1. Run Gitlab docker run --detach --hostname gitlab.example.com --publish 443:443 --publish 80:80 --publish 22:22 --name gitlab gitlab/gitlab-ce:latest

  2. Create a new project with README.md

  3. Go to Operations->Kubernetes

    1. Click on the "Add Kubernetes cluster" button
    2. Select the "Add existing cluster" tab
    3. Kubernetes cluster name: cluster-example
    4. API URL: https://google.com
    5. Service Token: token-example
    6. Uncheck the "GitLab-managed cluster" checkbox
    7. Click on the "Add Kubernetes cluster" button

  4. Add ".gitlab-ci.yml" file to the repository (to the master branch)

    deploy:  
  stage: deploy  
  script:  
    - echo "Example"  
  environment:  
    name: production  
    url: https://google.com  
    kubernetes:  
      namespace: <img src=x onerror=alert(1)>  
  only:  
  - master

  5. Go to CI/CD->Jobs and open the last job
    1.png
    2.png

Vulnerable code

All vulnerable code is in one file environments_block.vue

  1. Line 125
  2. Line 156
  3. Line 251
  4. And other places where %{kubernetesNamespace} is used

Impact

An attacker can:

  1. Perform any action within the application that a user can perform
  2. Steal sensitive user data
  3. Steal user's credentials

Attachments

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