Improper Control of Dynamically-Managed Code Resources, Unrestricted Upload of File with Dangerous Type, Inclusion of Functionality from Untrusted Control Sphere 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. In the affected versions, Solr ConfigSets accepted Java jar and class files to be uploaded through the ConfigSets API. When backing up Solr Collections, these configSet files would be saved to disk when using the LocalFileSystemRepository (the default for backups). If the backup was saved to a directory that Solr uses in its ClassPath/ClassLoaders, then the jar and class files would be available to use with any ConfigSet, trusted or untrusted. When Solr is run in a secure way (Authorization enabled), as is strongly suggested, this vulnerability is limited to extending the Backup permissions with the ability to add libraries. Users are recommended to upgrade to version 8.11.3 or 9.4.1, which fix the issue. In these versions, the following protections have been added: * Users are no longer able to upload files to a configSet that could be executed via a Java ClassLoader. * The Backup API restricts saving backups to directories that are used in the ClassLoader.

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.

Incorrect Permission Assignment for Critical Resource, Improper Control of Dynamically-Managed Code Resources vulnerability in Apache Solr. This issue affects Apache Solr: from 8.10.0 through 8.11.2, from 9.0.0 before 9.3.0. The Schema Designer was introduced to allow users to more easily configure and test new Schemas and configSets. However, when the feature was created, the "trust" (authentication) of these configSets was not considered. External library loading is only available to configSets that are "trusted" (created by authenticated users), thus non-authenticated users are unable to perform Remote Code Execution. Since the Schema Designer loaded configSets without taking their "trust" into account, configSets that were created by unauthenticated users were allowed to load external libraries when used in the Schema Designer. Users are recommended to upgrade to version 9.3.0, which fixes the issue.

Insufficiently Protected Credentials vulnerability in Apache Solr. This issue affects Apache Solr: from 6.0.0 through 8.11.2, from 9.0.0 before 9.3.0. One of the two endpoints that publishes the Solr process' Java system properties, /admin/info/properties, was only setup to hide system properties that had "password" contained in the name. There are a number of sensitive system properties, such as "basicauth" and "aws.secretKey" do not contain "password", thus their values were published via the "/admin/info/properties" endpoint. This endpoint populates the list of System Properties on the home screen of the Solr Admin page, making the exposed credentials visible in the UI. This /admin/info/properties endpoint is protected under the "config-read" permission. Therefore, Solr Clouds with Authorization enabled will only be vulnerable through logged-in users that have the "config-read" permission. Users are recommended to upgrade to version 9.3.0 or 8.11.3, which fixes the issue. A single option now controls hiding Java system property for all endpoints, "-Dsolr.hiddenSysProps". By default all known sensitive properties are hidden (including "-Dbasicauth"), as well as any property with a name containing "secret" or "password". Users who cannot upgrade can also use the following Java system property to fix the issue:   '-Dsolr.redaction.system.pattern=.*(password|secret|basicauth).*'

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.

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.