GHSA-hw6r-g8gj-2987: //github.com/pytorch/pytorch/.github/actions/filter test configs Actions Expression Injection Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hw6r-g8gj-2987",
  "modified" : "2023-08-30T20:47:13Z",
  "published" : "2023-08-30T20:47:13Z",
  "aliases" : [ ],
  "summary" : "Actions expression injection in `filter-test-configs` (`GHSL-2023-181`)",
  "details" : "The `pytorch/pytorch` `filter-test-configs` workflow is vulnerable to an expression injection in Actions, allowing an attacker to potentially leak secrets and alter the repository using the workflow.\n\n### Details\n\nThe [`filter-test-configs`](https://github.com/pytorch/pytorch/blob/ec26947c586dd323d741da80008403664c533f65/.github/actions/filter-test-configs/action.yml) workflow is using the raw `github.event.workflow_run.head_branch` value inside the `filter` step:\n\n```yaml\n- name: Select all requested test configurations\n  shell: bash\n  env:\n    GITHUB_TOKEN: ${{ inputs.github-token }}\n    JOB_NAME: ${{ steps.get-job-name.outputs.job-name }}\n  id: filter\n  run: |\n    ...\n    python3 \"${GITHUB_ACTION_PATH}/../../scripts/filter_test_configs.py\" \\\n      ...\n      --branch \"${{ github.event.workflow_run.head_branch }}\"\n```\n\nIn the event of a repository using `filter-test-configs` in a `pull_request_target`-triggered workflow, an attacker could use a malicious branch name to gain command execution in the step and potentially leak secrets.\n\n```yml\nname: Example\n\non: pull_request_target\n\njobs:\n  example:\n    runs-on: ubuntu-latest\n    steps:\n      - name: Filter\n        uses: pytorch/pytorch/.github/actions/filter-test-configs@v2\n```\n\n#### Impact\n\nThis issue may lead to stealing workflow secrets.\n\n#### Remediation\n\n1. Use an intermediate environment variable for potentially attacker-controlled values such as `github.event.workflow_run.head_branch`:\n```yaml\n- name: Select all requested test configurations\n  shell: bash\n  env:\n    GITHUB_TOKEN: ${{ inputs.github-token }}\n    JOB_NAME: ${{ steps.get-job-name.outputs.job-name }}\n    HEAD_BRANCH: ${{ github.event.workflow_run.head_branch }}\n  id: filter\n  run: |\n    ...\n    python3 \"${GITHUB_ACTION_PATH}/../../scripts/filter_test_configs.py\" \\\n      ...\n      --branch \"$HEAD_BRANCH\"\n```\n\n#### Resources\n\n* [CodeQL for JavaScript - Expression injection in Actions](https://codeql.github.com/codeql-query-help/javascript/js-actions-command-injection/)\n* [Keeping your GitHub Actions and workflows secure Part 2: Untrusted input](https://securitylab.github.com/research/github-actions-untrusted-input/)\n* [Keeping your GitHub Actions and workflows secure Part 1: Preventing pwn requests](https://securitylab.github.com/research/github-actions-preventing-pwn-requests/)\n",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "GitHub Actions",
      "name" : "https://github.com/pytorch/pytorch/.github/actions/filter-test-configs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 2.0.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pytorch/pytorch/security/advisories/GHSA-hw6r-g8gj-2987"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pytorch/pytorch"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-30T20:47:13Z",
    "nvd_published_at" : null
  }
}