CVE-2024-45293: PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. The security scanner responsible for preventing XXE attacks in the XLS...

Description

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. The security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. The security scan function in src/PhpSpreadsheet/Reader/Security/XmlScanner.php contains a flawed XML encoding check to retrieve the input file's XML encoding in the toUtf8 function. The function searches for the XML encoding through a defined regex which looks for `encoding="*"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. This logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the = in the attribute definition. Sensitive information disclosure through the XXE on sites that allow users to upload their own excel spreadsheets, and parse them using PHPSpreadsheet's Excel parser. This issue has been addressed in release versions 1.29.1, 2.1.1, and 2.3.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

2.86%

85.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Phpoffice	Phpspreadsheet	< 1.29.1
Phpoffice	Phpspreadsheet	>= 2.0.0, < 2.1.1
Phpoffice	Phpspreadsheet	>= 2.2.0, < 2.3.0

References

https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-6hwr-6v2f-3m88Exploit, Vendor Advisory

Timeline

Published: Oct 7, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-45293?

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. The security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. The security scan function in src/PhpSpreadsheet/Reader/Security/XmlScanner.php contains a flawed XML encoding check to retrieve the input file's XML encoding in the toUtf8 function. The function searches for the XML encoding through a defined regex which looks for `encoding="*"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. This logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the = in the attribute definition. Sensitive information disclosure through the XXE on sites that allow users to upload their own excel spreadsheets, and parse them using PHPSpreadsheet's Excel parser. This issue has been addressed in release versions 1.29.1, 2.1.1, and 2.3.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

How severe is CVE-2024-45293?

CVE-2024-45293 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.86% probability of exploitation in the next 30 days.

How do I fix CVE-2024-45293?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.