PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading

Overview

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0, Worksheet\Drawing::setPath validates only the initial external-image URL with setIsWhitelisted when setAllowExternalImages is enabled. The HTTP stream context permits PHP to follow a redirect without applying the callback to the redirected URL, so a permitted image host can redirect the server to an internal address and cause a blind GET request. The response body is not returned to the attacker because the reader validates the downloaded content as an image and removes the temporary file, but internal GET-driven endpoints, network reachability, and cloud metadata endpoints may be reached. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0.

Affected

• PhpSpreadsheet < 1.30.7
• PhpSpreadsheet >= 2.0.0, < 2.1.19
• PhpSpreadsheet >= 2.2.0, < 2.4.8
• PhpSpreadsheet >= 3.3.0, < 3.10.8
• PhpSpreadsheet >= 4.0.0, < 5.10.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.