Apache Solr Unprivileged users may be able to perform unauthorized read/write to collections

Vulnerability

Description

When using the ConfigurableInternodeAuthHadoopPlugin for authentication, Apache Solr versions prior to 8.8.2 improperly forward or proxy distributed requests using the server's own credentials instead of the original client's credentials [1]. This means that when a Solr node relays a request to another node in the cluster, it authenticates with its own internal credentials rather than preserving the client's authentication context.

Exploitation

An attacker who can submit requests to a Solr cluster can exploit this behavior. The forwarding node uses its own credentials, so the receiving node sees the request as coming from a trusted internal server, bypassing the intended client-level authorization checks [1]. No special network position is required beyond being able to reach the Solr cluster.

Impact

This flaw results in incorrect authorization resolution on the receiving hosts. An attacker could perform operations that should be restricted, such as accessing or modifying data they are not authorized to, because the receiving node trusts the forwarded request as if it originated from an internal server [1].

Mitigation

The vulnerability is fixed in Apache Solr version 8.8.2 [1]. Users should upgrade to this version or later. No workarounds are documented in the available reference.