Magento-lts is a long-term support alternative to Magento Community Edition (CE). A vulnerability in magento-lts versions before 19.4.13 and 20.0.9 potentially allows an administrator unauthorized access to restricted resources. This is a backport of CVE-2021-21024. The vulnerability is patched in versions 19.4.13 and 20.0.9.
https://github.com/OpenMage/magento-lts/security/advisories/GHSA-fvrf-9428-527m