CVE-2023-50298: Apache Solr: Solr can expose ZooKeeper credentials via Streaming Expressions

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-09 · updated 2026-06-17
Weakness: CWE-200

Description

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.

Affected products

Apache Software Foundation Apache Solr: from 6.0.0 before 8.11.3; from 9.0.0 before 9.4.1 — fixed in 8.11.3, 9.4.1

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Solr 8.11.3, 9.4.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2023-50298 or the next vulnerability affects your stack