CVE-2019-12331: PHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue. The XmlScanner decodes the sheet1.xml from an .xlsx to utf-8 if something else than UTF-8 is declared…

PriorityP340high8.8CVSS 3.1

AVNACLPRNUIRSUCHIHAH

EPSS

1.35%

68.0th percentile

PHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue. The XmlScanner decodes the sheet1.xml from an .xlsx to utf-8 if something else than UTF-8 is declared in the header. This was a security measurement to prevent CVE-2018-19277 but the fix is not sufficient. By double-encoding the the xml payload to utf-7 it is possible to bypass the check for the string ‚<!ENTITY‘ and thus allowing for an xml external entity processing (XXE) attack.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
phpoffice	phpexcel	0 – 1.8.2	—
phpoffice	phpspreadsheet	< 1.8.0	1.8.0
phpoffice	phpspreadsheet	>= 0 < 1.8.0	1.8.0

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvdv2.06.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P

ghsa8.8HIGH

osv8.8HIGH

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.