CVE-2023-50298 is a high-severity (CVSS 7.5) Information Exposure vulnerability in org.apache.solr:solr-solrj-streaming. A fix is available for org.apache.solr:solr-solrj-streaming — see the affected versions and patch details below.
Apache Solr: Solr can expose ZooKeeper credentials via Streaming Expressions
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-50298.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-50298 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.apache.solr:solr-solrj-streaming☕org.apache.solr:solr-solrj-streaming☕org.apache.solr:solr-solrj☕org.apache.solr:solr-solrjReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.solr:solr-solrj-streaming | ≥ 9.0.0&&< 9.4.1 | 9.4.1org.apache.solr:solr-solrj-streaming:9.4.1 |
| ☕Maven | org.apache.solr:solr-solrj-streaming | ≥ 6.0.0&&< 8.11.3 | 8.11.3org.apache.solr:solr-solrj-streaming:8.11.3 |
| ☕Maven | org.apache.solr:solr-solrj | ≥ 9.0.0&&< 9.4.1 | 9.4.1org.apache.solr:solr-solrj:9.4.1 |
| ☕Maven | org.apache.solr:solr-solrj | ≥ 6.0.0&&< 8.11.3 | 8.11.3org.apache.solr:solr-solrj:8.11.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.solr:solr-solrj-streaming, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.solr:solr-solrj-streaming to 9.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-50298 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-50298 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-50298. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-50298 in your dependencies?
O3 Security finds CVE-2023-50298 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.