Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Solr. This issue affects Apache Solr from 6.0.0 through 8.11.2, from 9.0.0 before 9.4.1.

Solr Streaming Expressions allows users to extract data from other Solr Clouds, using a "zkHost" parameter.

When original SolrCloud is setup to use ZooKeeper credentials and ACLs, they will be sent to whatever "zkHost" the user provides.

An attacker could setup a server to mock ZooKeeper, that accepts ZooKeeper requests with credentials and ACLs and extracts the sensitive information, then send a streaming expression using the mock server's address in "zkHost".

Streaming Expressions are exposed via the "/streaming" handler, with "read" permissions.

Users are recommended to upgrade to version 8.11.3 or 9.4.1, which fix the issue.

From these versions on, only zkHost values that have the same server address (regardless of chroot), will use the given ZooKeeper credentials and ACLs when connecting.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Solr.

The Solr Metrics API publishes all unprotected environment variables available to each Apache Solr instance. Users are able to specify which environment variables to hide, however, the default list is designed to work for known secret Java system properties. Environment variables cannot be strictly defined in Solr, like Java system properties can be, and may be set for the entire host, unlike Java system properties which are set per-Java-proccess.

The Solr Metrics API is protected by the "metrics-read" permission. Therefore, Solr Clouds with Authorization setup will only be vulnerable via users with the "metrics-read" permission.

This issue affects Apache Solr: from 9.0.0 before 9.3.0.

Users are recommended to upgrade to version 9.3.0 or later, in which environment variables are not published via the Metrics API.

Apache Solr could allow a remote attacker to execute arbitrary code on the system, caused by the Schema Designer blindly trusting all configsets. An attacker could exploit his vulnerability to execute arbitrary code on the system.

Apache Solr could allow a remote authenticated attacker to obtain sensitive information, caused by system property redaction logic inconsistencies. By using the /admin/info/properties endpoint, an attacker could exploit his vulnerability to leak certain passwords.

Apache Solr could allow a remote attacker to upload arbitrary files, caused by the improper control of dynamically-managed code resources. By using Backup/Restore APIs, a remote attacker could exploit this vulnerability to upload a malicious file, which could allow the attacker to execute arbitrary code on the vulnerable system.