OpenEMR is a free and open source electronic health records and medical practice management application. Versions prior to 8.0.0.3 have a missing authorization check in `portal/sign/lib/show-signature.php` that allows any authenticated patient portal user to retrieve the drawn signature image of any staff member by supplying an arbitrary `user` value in the POST body. The companion write endpoint (`save-signature.php`) was already hardened against this same issue, but the read endpoint was not updated to match. Version 8.0.0.3 patches the issue.
https://github.com/openemr/openemr/security/advisories/GHSA-w9w5-7x6h-657q
https://github.com/openemr/openemr/releases/tag/v8_0_0_3
https://github.com/openemr/openemr/commit/ae7ee1872d2e6300b165e24687cc90cf6847a4e5