CVE-2026-40557: CWE-295 Improper Certificate Validation in Apache Software Foundation Apache Storm Prometheus Reporter
Improper Certificate Validation via Global SSL Context Downgrade in Apache Storm Prometheus Reporter Versions Affected: from 2.6.3 to 2.8.6 Description: In production deployments where an administrator enables storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation (by default it is disabled) intending to affect only the Prometheus reporter, the undocumented global side effect creates an attack surface across every TLS-protected communication channel in the Storm daemon. The PrometheusPreparableReporter class implements an INSECURE_TRUST_MANAGER that accepts all SSL certificates without validation, with empty checkClientTrusted and checkServerTrusted methods. Most critically, when the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation configuration option is enabled (default = disabled) for HTTPS Prometheus PushGateway connections, the INSECURE_CONNECTION_FACTORY calls SSLContext.setDefault(sslContext), which globally replaces the JVM's default SSL context rather than applying the insecure context only to the Prometheus connection. This payload flows through storm.yaml configuration → PrometheusPreparableReporter.prepare() → INSECURE_CONNECTION_FACTORY → SSLContext.setDefault(), resulting in a JVM-wide TLS security downgrade. All subsequent HTTPS connections in the process - including ZooKeeper, Thrift, Netty, and UI connections - silently trust all certificates, including self-signed, expired, and attacker-generated ones, enabling man-in-the-middle interception of cluster state, topology submissions, tuple data, and administrative credentials. Mitigation: 2.x users should upgrade to 2.8.7 if the Prometheus Metrics Reporter is used. Prometheus Metrics Reporter Users who cannot upgrade immediately should remove the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation: true setting from their storm.yaml configuration and instead configure a proper truststore containing the PushGateway's certificate.
AI Analysis
Technical Summary
The vulnerability arises from the PrometheusPreparableReporter class in Apache Storm Prometheus Reporter, which implements an insecure trust manager that accepts all SSL certificates without validation. When the configuration storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation is set to true, the insecure SSL context is set globally via SSLContext.setDefault(), impacting all TLS connections in the JVM process. This results in a JVM-wide TLS security downgrade, allowing man-in-the-middle interception of sensitive data across various Storm daemon components. The issue affects versions 2.6.3 through 2.8.6 and is resolved in version 2.8.7.
Potential Impact
The vulnerability allows an attacker to perform man-in-the-middle attacks on all TLS-protected communications within the Storm daemon process, including ZooKeeper, Thrift, Netty, UI connections, and Prometheus PushGateway connections. This can lead to interception and potential compromise of cluster state, topology submissions, tuple data, and administrative credentials. The CVSS score is 4.8 (medium severity), reflecting limited impact on confidentiality and integrity with no impact on availability.
Mitigation Recommendations
A fix is available in Apache Storm version 2.8.7. Users of affected versions who utilize the Prometheus Metrics Reporter should upgrade to 2.8.7. If immediate upgrade is not possible, users must remove the configuration setting storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation: true from their storm.yaml file and instead configure a proper truststore containing the PushGateway's certificate to ensure secure TLS validation.
CVE-2026-40557: CWE-295 Improper Certificate Validation in Apache Software Foundation Apache Storm Prometheus Reporter
Description
Improper Certificate Validation via Global SSL Context Downgrade in Apache Storm Prometheus Reporter Versions Affected: from 2.6.3 to 2.8.6 Description: In production deployments where an administrator enables storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation (by default it is disabled) intending to affect only the Prometheus reporter, the undocumented global side effect creates an attack surface across every TLS-protected communication channel in the Storm daemon. The PrometheusPreparableReporter class implements an INSECURE_TRUST_MANAGER that accepts all SSL certificates without validation, with empty checkClientTrusted and checkServerTrusted methods. Most critically, when the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation configuration option is enabled (default = disabled) for HTTPS Prometheus PushGateway connections, the INSECURE_CONNECTION_FACTORY calls SSLContext.setDefault(sslContext), which globally replaces the JVM's default SSL context rather than applying the insecure context only to the Prometheus connection. This payload flows through storm.yaml configuration → PrometheusPreparableReporter.prepare() → INSECURE_CONNECTION_FACTORY → SSLContext.setDefault(), resulting in a JVM-wide TLS security downgrade. All subsequent HTTPS connections in the process - including ZooKeeper, Thrift, Netty, and UI connections - silently trust all certificates, including self-signed, expired, and attacker-generated ones, enabling man-in-the-middle interception of cluster state, topology submissions, tuple data, and administrative credentials. Mitigation: 2.x users should upgrade to 2.8.7 if the Prometheus Metrics Reporter is used. Prometheus Metrics Reporter Users who cannot upgrade immediately should remove the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation: true setting from their storm.yaml configuration and instead configure a proper truststore containing the PushGateway's certificate.
CVSS v3.1
Score 4.8medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises from the PrometheusPreparableReporter class in Apache Storm Prometheus Reporter, which implements an insecure trust manager that accepts all SSL certificates without validation. When the configuration storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation is set to true, the insecure SSL context is set globally via SSLContext.setDefault(), impacting all TLS connections in the JVM process. This results in a JVM-wide TLS security downgrade, allowing man-in-the-middle interception of sensitive data across various Storm daemon components. The issue affects versions 2.6.3 through 2.8.6 and is resolved in version 2.8.7.
Potential Impact
The vulnerability allows an attacker to perform man-in-the-middle attacks on all TLS-protected communications within the Storm daemon process, including ZooKeeper, Thrift, Netty, UI connections, and Prometheus PushGateway connections. This can lead to interception and potential compromise of cluster state, topology submissions, tuple data, and administrative credentials. The CVSS score is 4.8 (medium severity), reflecting limited impact on confidentiality and integrity with no impact on availability.
Mitigation Recommendations
A fix is available in Apache Storm version 2.8.7. Users of affected versions who utilize the Prometheus Metrics Reporter should upgrade to 2.8.7. If immediate upgrade is not possible, users must remove the configuration setting storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation: true from their storm.yaml file and instead configure a proper truststore containing the PushGateway's certificate to ensure secure TLS validation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-04-14T11:20:51.218Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69ef64deba26a39fba2863c8
Added to database: 4/27/2026, 1:30:06 PM
Last enriched: 5/5/2026, 2:13:11 AM
Last updated: 6/11/2026, 6:27:06 PM
Views: 71
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.