XXE in Phpoffice Phpspreadsheet
CVE-2024-48917
PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. The `XmlScanner` class has a scan method which should prevent XXE attacks. However, in a bypass of the previously reported `CVE-2024-47873`, the regexes from the `findCharSet` method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value `encoding="UTF-8"` with `"`, which is matched by the first regex, so that `encoding='UTF-7'` with single quotes `'` in the XML header is not matched by the second regex. An attacker can bypass the sanitizer and achieve an XML external entity attack. Versions 1.9.4, 2.1.3, 2.3.2, and 3.4.0 fix the issue.
Vulnerability class: XXE (XML External Entity)
EPSS: 0.007 (52.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Phpoffice Phpspreadsheet — versions < 1.29.4, >= 2.0.0, < 2.1.3, >= 2.2.0, < 2.3.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Not Applicable)
Frequently asked questions
- What is CVE-2024-48917?
- CVE-2024-48917 is a high-severity vulnerability in Phpoffice Phpspreadsheet, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2024-11-18.
- How severe is CVE-2024-48917?
- High severity. CVSS v3 base score is 7.5 out of 10.