CVE-2016-1000221 is a high-severity (CVSS 7.5) Information Exposure vulnerability in logstash-core. A fix is available for logstash-core — see the affected versions and patch details below.
Logstash Logs Sensitive Information
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
logstash-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Logstash prior to version 2.3.4, Elasticsearch Output plugin would log to file HTTP authorization headers which could contain sensitive information.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | logstash-core | all versions | 2.3.4bundle update logstash-core --conservative |
Affected Products
logstashelasticDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for logstash-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update logstash-core to 2.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-1000221 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2016-1000221 in your dependencies?
Find it across RubyGems, including transitive dependencies.