TL;DR
Hardcoded credentials in the Basic Authentication setup tool (bin/solr auth enable) in Apache Solr versions 9.4.0 through 9.10.1 and 10.0.0 allows a remote attacker to gain full administrative access to the cluster via publicly known default credentials installed silently alongside the user-specified account. As an immediate workaround without upgrading, delete the template users (superadmin, admi…