ghsa-j55r-787p-m549
Vulnerability from github
Published
2023-08-22 18:00
Modified
2023-09-01 19:46
Severity ?
8.6 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Summary
Shescape on Windows escaping may be bypassed in threaded context
Details

Impact

This may impact users that use Shescape on Windows in a threaded context (e.g. using Worker threads). The vulnerability can result in Shescape escaping (or quoting) for the wrong shell, thus allowing attackers to bypass protections depending on the combination of expected and used shell.

This snippet demonstrates a vulnerable use of Shescape:

```javascript // vulnerable.js

import { exec } from "node:child_process"; import { Worker, isMainThread } from 'node:worker_threads';

import * as shescape from "shescape";

if (isMainThread) { // 1. Something like a worker thread must be used. The reason being that they // unexpectedly change environment variable names on Windows. new Worker("./vulnerable.js"); } else { // 2. Example configuration that's problematic. In this setup example the // expected default system shell is CMD. We configure the use of PowerShell. // Shescape will fail to look up PowerShell and default to escaping for CMD // instead, resulting in the vulnerability. const options = { shell: "powershell", interpolation: true, };

// 3. Using shescape to protect against attacks, this is correct. const escaped = shescape.escape("&& ls", options);

// 4. Invoking a command with the escaped user input, this is vulnerable in // this case. exec(echo Hello ${escaped}, options, (error, stdout) => { if (error) { console.error(An error occurred: ${error}); } else { console.log(stdout); } }); } ```

Patches

This bug has been patched in v1.7.4 which you can upgrade to now. No further changes are required.

Workarounds

If you are impacted there is no workaround possible.

References

For more information

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "shescape"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.7.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-40185"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-150"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-08-22T18:00:04Z",
    "nvd_published_at": "2023-08-23T21:15:09Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nThis may impact users that use Shescape on Windows in a threaded context (e.g. using [Worker threads](https://nodejs.org/api/worker_threads.html)). The vulnerability can result in Shescape escaping (or quoting) for the wrong shell, thus allowing attackers to bypass protections depending on the combination of expected and used shell.\n\nThis snippet demonstrates a vulnerable use of Shescape:\n\n```javascript\n// vulnerable.js\n\nimport { exec } from \"node:child_process\";\nimport { Worker, isMainThread } from \u0027node:worker_threads\u0027;\n\nimport * as shescape from \"shescape\";\n\nif (isMainThread) {\n  // 1. Something like a worker thread must be used. The reason being that they\n  // unexpectedly change environment variable names on Windows.\n  new Worker(\"./vulnerable.js\");\n} else {\n  // 2. Example configuration that\u0027s problematic. In this setup example the\n  // expected default system shell is CMD. We configure the use of PowerShell.\n  // Shescape will fail to look up PowerShell and default to escaping for CMD\n  // instead, resulting in the vulnerability.\n  const options = {\n    shell: \"powershell\",\n    interpolation: true,\n  };\n\n  // 3. Using shescape to protect against attacks, this is correct.\n  const escaped = shescape.escape(\"\u0026\u0026 ls\", options);\n\n  // 4. Invoking a command with the escaped user input, this is vulnerable in\n  // this case.\n  exec(`echo Hello ${escaped}`, options, (error, stdout) =\u003e {\n    if (error) {\n      console.error(`An error occurred: ${error}`);\n    } else {\n      console.log(stdout);\n    }\n  });\n}\n```\n\n### Patches\n\nThis bug has been patched in [v1.7.4](https://github.com/ericcornelissen/shescape/releases/tag/v1.7.4) which you can upgrade to now. No further changes are required.\n\n### Workarounds\n\nIf you are impacted there is no workaround possible.\n\n### References\n\n- Shescape Pull Request [#1142](https://github.com/ericcornelissen/shescape/pull/1142)\n- Shescape commit [`0b976da`](https://github.com/ericcornelissen/shescape/commit/0b976dab645abf45ffd85e74a8c6e51ee2f42d63)\n- Shescape release [v1.7.4](https://github.com/ericcornelissen/shescape/releases/tag/v1.7.4)\n\n### For more information\n\n- Comment on Pull Request [#1142](https://github.com/ericcornelissen/shescape/pull/1142)\n- Comment on commit [`0b976da`](https://github.com/ericcornelissen/shescape/commit/0b976dab645abf45ffd85e74a8c6e51ee2f42d63)\n- Open an issue at [https://github.com/ericcornelissen/shescape/issues](https://github.com/ericcornelissen/shescape/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc) (New issue \u003e Question \u003e Get started)",
  "id": "GHSA-j55r-787p-m549",
  "modified": "2023-09-01T19:46:34Z",
  "published": "2023-08-22T18:00:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/security/advisories/GHSA-j55r-787p-m549"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-40185"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/pull/1142"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/commit/0b976dab645abf45ffd85e74a8c6e51ee2f42d63"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ericcornelissen/shescape"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ericcornelissen/shescape/releases/tag/v1.7.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Shescape on Windows escaping may be bypassed in threaded context"
}


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.