Threats tagged 'ghsa-3x94-m842-937c'

PhpSpreadsheet versions prior to 5.10.0, 3.10.8, 2.4.8, 2.1.19, and 1.30.7 contain a vulnerability in the XmlScanner::scan() method. The scanner's regex pattern only accounts for NULL byte interleaving when detecting <!DOCTYPE declarations, but ISO-2022 escape sequences can bypass this detection. This allows malicious XLSX files with crafted XML to include DOCTYPE declarations that enable XML External Entity (XXE) attacks and Denial of Service (DoS) via quadratic entity expansion. The issue affects all PHP versions for DoS and PHP versions below 8.0 or when LIBXML_NOENT is used for XXE/SSRF. A fix is available in the stated versions.