CVE-2024-45293 XML External Entity Reference (XXE) in PHPSpreadsheet's XLSX reader

High 7.5 Published 7 Oct 2024 Updated 7 Oct 2024

Attackers can disclose sensitive server files by uploading crafted XLSX files to applications using PHPSpreadsheet, bypassing XML security checks.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2024-45293?

CVE-2024-45293 is a high-severity vulnerability in PHPOffice PhpSpreadsheet, published on 7 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-611

Which versions are affected by CVE-2024-45293?

8 open source packages ship an affected version, including phpoffice/phpspreadsheet and phpoffice/phpexcel. It affects 1 product.

Package	Affected	Fixed in
`phpoffice/phpspreadsheet` Packagist	All versions	`1.29.1`
`phpoffice/phpspreadsheet` Packagist	All versions	`1.29.1`
`phpoffice/phpspreadsheet` Packagist	From `2.0.0`	`2.1.1`
`phpoffice/phpspreadsheet` Packagist	From `2.0.0`	`2.1.1`
`phpoffice/phpspreadsheet` Packagist	From `2.2.0`	`2.3.0`
`phpoffice/phpspreadsheet` Packagist	From `2.2.0`	`2.3.0`

2 more packages

`phpoffice/phpexcel` Packagist	All versions to `1.8.2`	None
`phpoffice/phpexcel` Packagist	All versions to `1.8.2`	None

Products include Phpoffice Phpspreadsheet.

How do I fix CVE-2024-45293?

Upgrade phpoffice/phpspreadsheet to a fixed version for your release line: 1.29.1, 2.1.1 or 2.3.0.

Is CVE-2024-45293 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-45293 exists.

Public exploit code: 1 Nuclei template.

Sources

Also known as GHSA-6hwr-6v2f-3m88.