Hardcoded credentials in the Basic Authentication setup tool (bin/solr auth enable) in Apache Solr versions 9.4.0 through 9.10.1 and 10.0.0 allows a remote attacker to gain full administrative access to the cluster via publicly known default credentials installed silently alongside the user-specified account.

As an immediate workaround without upgrading, delete the template users (superadmin, admin, search, index) from security.json or change their passwords. The future, not yet released, versions 9.11.0 and 10.1.0 will not be vulnerable, and it will be enough to upgrade to solve the issue.

Not affected: Clusters where bin/solr auth enable was not used to bootstrap BasicAuth Clusters where template users have been assigned strong passwords after bootstrap

An Improper Input Validation vulnerability in DataImportHandler of Apache Solr allows an attacker to provide a Windows UNC path resulting in an SMB network call being made from the Solr host to another host on the network. If the attacker has wider access to the network, this may lead to SMB attacks, which may result in: The exfiltration of sensitive data such as OS user hashes (NTLM/LM hashes), In case of misconfigured systems, SMB Relay Attacks which can lead to user impersonation on SMB Shares or, in a worse-case scenario, Remote Code Execution This issue affects all Apache Solr versions prior to 8.11.1. This issue only affects Windows.

When using ConfigurableInternodeAuthHadoopPlugin for authentication, Apache Solr versions prior to 8.8.2 would forward/proxy distributed requests using server credentials instead of original client credentials. This would result in incorrect authorization resolution on the receiving hosts.

The ReplicationHandler (normally registered at "/replication" under a Solr core) in Apache Solr has a "masterUrl" (also "leaderUrl" alias) parameter that is used to designate another ReplicationHandler on another Solr core to replicate index data into the local core. To prevent a SSRF vulnerability, Solr ought to check these parameters against a similar configuration it uses for the "shards" parameter. Prior to this bug getting fixed, it did not. This problem affects essentially all Solr versions prior to it getting fixed in 8.8.2.

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.

The 8.1.1 and 8.2.0 releases of Apache Solr contain an insecure setting for the ENABLEREMOTEJMXOPTS 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 RMIPORT (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.

A flaw was found in the Apache Solr's Config API, where it would permit the configuration of the JMX server via an HTTP POST request. An attacker could use this flaw to direct traffic to a malicious RMI server, and then trigger remote code execution or conduct further attacks.

It was found that Apache Solr would accept an object from an unauthenticated user that could be manipulated through subsequent post requests. An attacker could use this flaw to assemble an object that could permit execution of arbitrary code on the server.