ghsa-3g7p-8qhx-mc8r
Vulnerability from github
Published
2023-06-22 20:01
Modified
2023-06-26 16:35
Severity ?
3.1 (Low) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Summary
Shescape potential environment variable exposure on Windows with CMD
Details

Impact

This impact users of Shescape:

  1. On Windows using the Windows Command Prompt (i.e. cmd.exe), and
  2. Using quote/quoteAll or escape/escapeAll with the interpolation option set to true.

An attacker may be able to get read-only access to environment variables. Example:

```javascript import * as cp from "node:child_process"; import * as shescape from "shescape";

// 1. Prerequisites const options = { shell: "cmd.exe", // Or shell: undefined, // Only if the default shell is CMD

// And
interpolation: true, // Only applies to `escape` and `escapeAll` usage

}

// 2. Attack (one of many) const payload = "%PATH%";

// 3. Usage let escapedPayload;

escapedPayload = shescape.quote(payload, options); // Or escapedPayload = shescape.quoteAll([payload], options); // Or escapedPayload = shescape.escape(payload, options); // Or escapedPayload = shescape.escapeAll([payload], options);

// And (example) const result = cp.execSync(echo Hello ${escapedPayload}, options);

// 4. Impact console.log(result.toString()); // Outputs "Hello" followed by the contents of the PATH environment variable ```

Patches

This bug has been patched in v1.7.1 which you can upgrade to now. No further changes are required.

Workarounds

Alternatively, users can remove all instances of % from user input, either before or after using Shescape.

References

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "shescape"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.7.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-35931"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-526"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-06-22T20:01:39Z",
    "nvd_published_at": "2023-06-23T20:15:09Z",
    "severity": "LOW"
  },
  "details": "### Impact\n\nThis impact users of Shescape:\n\n1. On Windows using the Windows Command Prompt (i.e. `cmd.exe`), and\n2. Using `quote`/`quoteAll` or `escape`/`escapeAll` with the `interpolation` option set to `true`.\n\nAn attacker may be able to get read-only access to environment variables. Example:\n\n```javascript\nimport * as cp from \"node:child_process\";\nimport * as shescape from \"shescape\";\n\n// 1. Prerequisites\nconst options = {\n    shell: \"cmd.exe\",\n    // Or\n    shell: undefined, // Only if the default shell is CMD\n\n    // And\n    interpolation: true, // Only applies to `escape` and `escapeAll` usage\n}\n\n// 2. Attack (one of many)\nconst payload = \"%PATH%\";\n\n// 3. Usage\nlet escapedPayload;\n\nescapedPayload = shescape.quote(payload, options);\n// Or\nescapedPayload = shescape.quoteAll([payload], options);\n// Or\nescapedPayload = shescape.escape(payload, options);\n// Or\nescapedPayload = shescape.escapeAll([payload], options);\n\n// And (example)\nconst result = cp.execSync(`echo Hello ${escapedPayload}`, options);\n\n// 4. Impact\nconsole.log(result.toString());\n// Outputs \"Hello\" followed by the contents of the PATH environment variable\n```\n\n### Patches\n\nThis bug has been patched in [v1.7.1](https://github.com/ericcornelissen/shescape/releases/tag/v1.7.1) which you can upgrade to now. No further changes are required.\n\n### Workarounds\n\nAlternatively, users can remove all instances of `%` from user input, either before or after using Shescape.\n\n### References\n\n- Shescape Pull request [#982](https://github.com/ericcornelissen/shescape/pull/982)\n- Shescape commit [`d0fce70`](https://github.com/ericcornelissen/shescape/commit/d0fce70f987ac0d8331f93cb45d47e79436173ac)\n- Shescape Release [v1.7.1](https://github.com/ericcornelissen/shescape/releases/tag/v1.7.1)\n",
  "id": "GHSA-3g7p-8qhx-mc8r",
  "modified": "2023-06-26T16:35:03Z",
  "published": "2023-06-22T20:01:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/security/advisories/GHSA-3g7p-8qhx-mc8r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-35931"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/pull/982"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/commit/d0fce70f987ac0d8331f93cb45d47e79436173ac"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ericcornelissen/shescape"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/releases/tag/v1.7.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Shescape potential environment variable exposure on Windows with CMD"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.