{"id":"GHSA-q9jv-mm3r-j47r","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\u003c?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-\u003egenerateHTMLAll());\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	ascript:alert()\njav
ascript:alert()\njav
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\u003cimg width=\"373\" alt=\"fig13\" src=\"https://github.com/user-attachments/assets/3ca0c3c6-daa9-4502-ad9e-b803f308fd26\" /\u003e\n\n*Figure 13. Executing arbitrary JavaScript code*\n\n# Credit\nThis vulnerability was discovered by **Aleksey Solovev (Positive Technologies)**","aliases":["CVE-2024-56412"],"modified":"2025-03-06T18:38:10.072150Z","published":"2025-01-03T17:29:10Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2025-01-03T17:29:10Z","nvd_published_at":"2025-01-03T18:15:16Z","cwe_ids":["CWE-79"],"severity":"MODERATE"},"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"}],"affected":[{"package":{"name":"phpoffice/phpspreadsheet","ecosystem":"Packagist","purl":"pkg:composer/phpoffice/phpspreadsheet"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.7.0"}]}],"versions":["3.3.0","3.4.0","3.5.0","3.6.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-q9jv-mm3r-j47r/GHSA-q9jv-mm3r-j47r.json"}},{"package":{"name":"phpoffice/phpspreadsheet","ecosystem":"Packagist","purl":"pkg:composer/phpoffice/phpspreadsheet"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.29.7"}]}],"versions":["1.0.0","1.0.0-beta","1.0.0-beta2","1.1.0","1.10.0","1.10.1","1.11.0","1.12.0","1.13.0","1.14.0","1.14.1","1.15.0","1.16.0","1.17.0","1.17.1","1.18.0","1.19.0","1.2.0","1.2.1","1.20.0","1.21.0","1.22.0","1.23.0","1.24.0","1.24.1","1.25.0","1.25.1","1.25.2","1.26.0","1.27.0","1.27.1","1.28.0","1.29.0","1.29.1","1.29.2","1.29.4","1.29.5","1.29.6","1.3.0","1.3.1","1.4.0","1.4.1","1.5.0","1.5.1","1.5.2","1.6.0","1.7.0","1.8.0","1.8.1","1.8.2","1.9.0"],"database_specific":{"last_known_affected_version_range":"\u003c= 1.29.6","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-q9jv-mm3r-j47r/GHSA-q9jv-mm3r-j47r.json"}},{"package":{"name":"phpoffice/phpspreadsheet","ecosystem":"Packagist","purl":"pkg:composer/phpoffice/phpspreadsheet"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.1.6"}]}],"versions":["2.0.0","2.1.0","2.1.1","2.1.3","2.1.4","2.1.5"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-q9jv-mm3r-j47r/GHSA-q9jv-mm3r-j47r.json","last_known_affected_version_range":"\u003c= 2.1.5"}},{"package":{"name":"phpoffice/phpspreadsheet","ecosystem":"Packagist","purl":"pkg:composer/phpoffice/phpspreadsheet"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.2.0"},{"fixed":"2.3.5"}]}],"versions":["2.2.0","2.2.1","2.2.2","2.3.0","2.3.2","2.3.3","2.3.4"],"database_specific":{"last_known_affected_version_range":"\u003c= 2.3.4","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-q9jv-mm3r-j47r/GHSA-q9jv-mm3r-j47r.json"}},{"package":{"name":"phpoffice/phpexcel","ecosystem":"Packagist","purl":"pkg:composer/phpoffice/phpexcel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.8.2"}]}],"versions":["1.7.9","1.7.9-rc1","1.8.0","1.8.0rc1","1.8.0rc2","1.8.0rc3","1.8.0rc4","1.8.1","1.8.2"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-q9jv-mm3r-j47r/GHSA-q9jv-mm3r-j47r.json"}}],"schema_version":"1.9.0","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"}]}