CVE-2024-56412: Phpoffice/phpspreadsheet Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q9jv-mm3r-j47r",
  "modified" : "2025-03-06T18:16:56Z",
  "published" : "2025-01-03T17:29:10Z",
  "aliases" : [ "CVE-2024-56412" ],
  "summary" : "PhpSpreadsheet allows bypass XSS sanitizer using the javascript protocol and special characters",
  "details" : "# Bypass XSS sanitizer using the javascript protocol and special characters\n\n**Product**: Phpspreadsheet\n**Version**: version 3.6.0\n**CWE-ID**: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')\n**CVSS vector v.3.1**: 5.4 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N)\n**CVSS vector v.4.0**: 4.8 (AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N)\n**Description**: an attacker can use special characters, so that the library processes the javascript protocol with special characters and generates an HTML link\n**Impact**: executing arbitrary JavaScript code in the browser\n**Vulnerable component**: class `PhpOffice\\PhpSpreadsheet\\Writer\\Html`, method `generateRow`\n**Exploitation conditions**: a user viewing a specially generated Excel file\n**Mitigation**: additional sanitization of special characters in a string\n**Researcher**: Aleksey Solovev (Positive Technologies)\n\n# Research\n\nThe researcher discovered zero-day vulnerability Bypass XSS sanitizer using the javascript protocol and special characters in Phpspreadsheet.\n\nThe following code is written on the server, which translates the XLSX file into a HTML representation and displays it in the response.\n\n*Listing 6. Source code on the server*\n\n```\n<?php\n\nrequire __DIR__ . '/vendor/autoload.php';\n\n$inputFileName = './doc/Book1.xlsx';\n$spreadsheet = \\PhpOffice\\PhpSpreadsheet\\IOFactory::load($inputFileName);\n$writer = new \\PhpOffice\\PhpSpreadsheet\\Writer\\Html($spreadsheet);\nprint($writer->generateHTMLAll());\n```\n\nAn attacker can use special characters so that this library processes the javascript protocol with special characters and generates a HTML link.\nThe Excel file is unpacked and a hyperlink in the file is inserted into the `xl/worksheets/sheet1.xml` file.\n\n![fig11](https://github.com/user-attachments/assets/b9d53f7a-6f36-4853-95f9-8aa22f81eccd)\n\n*Figure 11. Using the javascript protocol with special characters*\n\nSome payloads help bypass the security system and carry out a XSS attack.\n\n*Listing 7. HTML form that demonstrates the exploitation of the XSS vulnerability*\n\n```\njav&#x09;ascript:alert()\njav&#x0D;ascript:alert()\njav&#x0A;ascript:alert()\n```\n\nIt's clear that the javascript protocol with special characters is used. \n\n![fig12](https://github.com/user-attachments/assets/7595e88b-9848-4251-845c-2c2d8032e479)\n\n*Figure 12. Using the javascript protocol with special characters*\n\nDue to the special characters, the execution stream ends up on line 1543, and the link is built in HTML form with the javascript protocol.\n\n<img width=\"373\" alt=\"fig13\" src=\"https://github.com/user-attachments/assets/3ca0c3c6-daa9-4502-ad9e-b803f308fd26\" />\n\n*Figure 13. Executing arbitrary JavaScript code*\n\n# Credit\nThis vulnerability was discovered by **Aleksey Solovev (Positive Technologies)**",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpoffice/phpspreadsheet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.7.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpoffice/phpspreadsheet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.29.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.29.6"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpoffice/phpspreadsheet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.1.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.1.5"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpoffice/phpspreadsheet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.2.0"
      }, {
        "fixed" : "2.3.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.3.4"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpoffice/phpexcel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.8.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-q9jv-mm3r-j47r"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-56412"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/PHPOffice/PhpSpreadsheet/commit/45052f88e04c735d56457a8ffcdc40b2635a028e"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/PHPOffice/PhpSpreadsheet"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-01-03T17:29:10Z",
    "nvd_published_at" : "2025-01-03T18:15:16Z"
  }
}