solr

In Apache Solr, the cluster can be partitioned into multiple collections and only a subset of nodes actually host any given collection. However, if a node receives a request for a collection it does not host, it proxies the request to a relevant node and serves the request. Solr bypasses all authorization settings for such requests. This affects all Solr versions prior to 7.7 that use the default authorization mechanism of Solr (RuleBasedAuthorizationPlugin).

In Apache Hadoop 3.2.0 to 3.2.1, 3.0.0-alpha1 to 3.1.3, and 2.0.0-alpha to 2.10.0, WebHDFS client might send SPNEGO authorization header to remote URL without proper verification.

Reported in SOLR-14515 (private) and fixed in SOLR-14561 (public), released in Solr version 8.6.0. The Replication handler (https://lucene.apache.org/solr/guide/8_6/index-replication.html#http-api-commands-for-the-replicationhandler) allows commands backup, restore and deleteBackup. Each of these take a location parameter, which was not validated, i.e you could read/write to any location the solr user can access.

Apache Solr versions 6.6.0 to 6.6.6, 7.0.0 to 7.7.3 and 8.0.0 to 8.6.2 prevents some features considered dangerous (which could be used for remote code execution) to be configured in a ConfigSet that’s uploaded via API without authentication/authorization. The checks in place to prevent such features can be circumvented by using a combination of UPLOAD/CREATE actions.

Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).

Solr versions 1.3.0 to 1.4.1, 3.1.0 to 3.6.2 and 4.0.0 to 4.10.4 are vulnerable to an XML resource consumption attack (a.k.a. Lol Bomb) via it’s update handler.?By leveraging XML DOCTYPE and ENTITY type elements, the attacker can create a pattern that will expand when the server parses the XML causing OOMs.