Apache Solr

SSRF vulnerability with the Replication handler

Remote code execution occurs in Apache Solr before 7.1 with Apache Lucene before 7.1 by exploiting XXE in conjunction with use of a Config API add-listener command to reach the RunExecutableListener class. Elasticsearch, although it uses Lucene, is NOT vulnerable to this. Note that the XML external entity expansion vulnerability occurs in the XML Query Parser which is available, by default, for any query request with parameters deftype=xmlparser and can be exploited to upload malicious data to the /upload request handler or as Blind XXE using ftp wrapper in order to read arbitrary local files from the Solr server. Note also that the second vulnerability relates to remote code execution using the RunExecutableListener available on all affected versions of Solr.

Apache Solr: Authentication bypass possible using a fake URL Path ending

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.

In Apache Solr versions 5.0.0 to 5.5.5 and 6.0.0 to 6.6.5, the Config API allows to configure the JMX server via an HTTP POST request. By pointing it to a malicious RMI server, an attacker could take advantage of Solr's unsafe deserialization to trigger remote code execution on the Solr side.

The 8.1.1 and 8.2.0 releases of Apache Solr contain an insecure setting for the ENABLE_REMOTE_JMX_OPTS configuration option in the default solr.in.sh configuration file shipping with Solr. If you use the default solr.in.sh file from the affected releases, then JMX monitoring will be enabled and exposed on RMI_PORT (default=18983), without any authentication. If this port is opened for inbound traffic in your firewall, then anyone with network access to your Solr nodes will be able to access JMX, which may in turn allow them to upload malicious code for execution on the Solr server.

Apache Solr information disclosure vulnerability through DataImportHandler

Apache Solr: Enabling BasicAuth using bin/solr CLI configures additional insecure users

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

SimpleXML (latest version 2.7.1) is vulnerable to an XXE vulnerability resulting SSRF, information disclosure, DoS and so on.

In Apache Solr, the DataImportHandler, an optional but popular module to pull in data from databases and other sources, has a feature in which the whole DIH configuration can come from a request's "dataConfig" parameter. The debug mode of the DIH admin screen uses this to allow convenient debugging / development of a DIH config. Since a DIH config can contain scripts, this parameter is a security risk. Starting with version 8.2.0 of Solr, use of this parameter requires setting the Java System property "enable.dih.dataConfigParam" to true.

Apache Solr: Backup/Restore APIs allow for deployment of executables in malicious ConfigSets

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: Unauthorized bypass of certain "predefined permission" rules in the RuleBasedAuthorizationPlugin

Apache Solr: ConfigSets created during a backup restore command are trusted implicitly

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.

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).

This vulnerability in Apache Solr 1.2 to 6.6.2 and 7.0.0 to 7.2.1 relates to an XML external entity expansion (XXE) in the `&dataConfig=<inlinexml>` parameter of Solr's DataImportHandler. It can be used as XXE using file/ftp/http protocols in order to read arbitrary local files from the Solr server or the internal network.

Server Side Request Forgery in Apache Solr, versions 1.3 until 7.6 (inclusive). Since the "shards" parameter does not have a corresponding whitelist mechanism, a remote attacker with access to the server could make Solr perform an HTTP GET request to any reachable URL.

An XXE issue in SAXBuilder in JDOM through 2.0.6 allows attackers to cause a denial of service via a crafted HTTP request.

The (1) UpdateRequestHandler for XSLT or (2) XPathEntityProcessor in Apache Solr before 4.1 allows remote attackers to have an unspecified impact via XML data containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue, different vectors than CVE-2013-6407.

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.

Misapplied Zookeeper ACLs can result in leakage of configured authentication and authorization settings

When using the Index Replication feature, Apache Solr nodes can pull index files from a master/leader node using an HTTP API which accepts a file name. However, Solr before 5.5.4 and 6.x before 6.4.1 did not validate the file name, hence it was possible to craft a special request involving path traversal, leaving any file readable to the Solr server process exposed. Solr servers protected and restricted by firewall rules and/or authentication would not be at risk since only trusted clients and users would gain direct HTTP access.

Apache Solr uses a PKI based mechanism to secure inter-node communication when security is enabled. It is possible to create a specially crafted node name that does not exist as part of the cluster and point it to a malicious node. This can trick the nodes in cluster to believe that the malicious node is a member of the cluster. So, if Solr users have enabled BasicAuth authentication mechanism using the BasicAuthPlugin or if the user has implemented a custom Authentication plugin, which does not implement either "HttpClientInterceptorPlugin" or "HttpClientBuilderPlugin", his/her servers are vulnerable to this attack. Users who only use SSL without basic authentication or those who use Kerberos are not affected.

Apache Solr: System Property redaction logic inconsistency can lead to leaked passwords

Apache Solr: Solr Schema Designer blindly "trusts" all configsets, possibly leading to RCE by unauthenticated users

Apache Solr's Kerberos plugin can be configured to use delegation tokens, which allows an application to reuse the authentication of an end-user or another application. There are two issues with this functionality (when using SecurityAwareZkACLProvider type of ACL provider e.g. SaslZkACLProvider). Firstly, access to the security configuration can be leaked to users other than the solr super user. Secondly, malicious users can exploit this leaked configuration for privilege escalation to further expose/modify private data and/or disrupt operations in the Solr cluster. The vulnerability is fixed from Apache Solr 6.6.1 onwards.

Apache Solr: Solr can expose ZooKeeper credentials via Streaming Expressions

Apache Solr: Insufficient file-access checking in standalone core-creation requests

Apache Solr: Host environment variables are published via the Metrics API

The DocumentAnalysisRequestHandler in Apache Solr before 4.3.1 does not properly use the EmptyEntityResolver, which allows remote attackers to have an unspecified impact via XML data containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue. NOTE: this vulnerability exists because of an incomplete fix for CVE-2013-6407.

The UpdateRequestHandler for XML in Apache Solr before 4.1 allows remote attackers to have an unspecified impact via XML data containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.

Cross-site scripting (XSS) vulnerability in webapp/web/js/scripts/schema-browser.js in the Admin UI in Apache Solr before 5.3 allows remote attackers to inject arbitrary web script or HTML via a crafted schema-browse URL.

Cross-site scripting (XSS) vulnerability in webapp/web/js/scripts/plugins.js in the stats page in the Admin UI in Apache Solr before 5.3.1 allows remote attackers to inject arbitrary web script or HTML via the entry parameter to a plugins/cache URI.

Multiple cross-site scripting (XSS) vulnerabilities in the Admin UI in Apache Solr before 5.1 allow remote attackers to inject arbitrary web script or HTML via crafted fields that are mishandled during the rendering of the (1) Analysis page, related to webapp/web/js/scripts/analysis.js or (2) Schema-Browser page, related to webapp/web/js/scripts/schema-browser.js.

This vulnerability in Apache Solr 6.0.0 to 6.6.4 and 7.0.0 to 7.3.1 relates to an XML external entity expansion (XXE) in Solr config files (currency.xml, enumsConfig.xml referred from schema.xml, TIKA parsecontext config file). In addition, Xinclude functionality provided in these config files is also affected in a similar way. The vulnerability can be used as XXE using file/ftp/http protocols in order to read arbitrary local files from the Solr server or the internal network. The manipulated files can be uploaded as configsets using Solr's API, allowing to exploit that vulnerability.

This vulnerability in Apache Solr 6.0.0 to 6.6.3, 7.0.0 to 7.3.0 relates to an XML external entity expansion (XXE) in Solr config files (solrconfig.xml, schema.xml, managed-schema). In addition, Xinclude functionality provided in these config files is also affected in a similar way. The vulnerability can be used as XXE using file/ftp/http protocols in order to read arbitrary local files from the Solr server or the internal network. Users are advised to upgrade to either Solr 6.6.4 or Solr 7.3.1 releases both of which address the vulnerability. Once upgrade is complete, no other steps are required. Those releases only allow external entities and Xincludes that refer to local files / zookeeper resources below the Solr instance directory (using Solr's ResourceLoader); usage of absolute URLs is denied. Keep in mind, that external entities and XInclude are explicitly supported to better structure config files in large installations. Before Solr 6 this was no problem, as config files were not accessible through the APIs.

Apache Solr: Core-creation with "trusted" configset can use arbitrary untrusted files