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.
References
| Link | Resource |
|---|---|
| https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/04/25/2 | Mailing List Third Party Advisory |
Configurations
History
05 May 2026, 18:11
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:apache:storm_prometheus_reporter:*:*:*:*:*:*:*:* | |
| References | () https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq - Mailing List, Vendor Advisory | |
| References | () http://www.openwall.com/lists/oss-security/2026/04/25/2 - Mailing List, Third Party Advisory | |
| First Time |
Apache storm Prometheus Reporter
Apache |
30 Apr 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 4.8 |
27 Apr 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-27 14:16
Updated : 2026-06-17 10:45
NVD link : CVE-2026-40557
Mitre link : CVE-2026-40557
CVE.ORG link : CVE-2026-40557
JSON object : View
Products Affected
apache
- storm_prometheus_reporter
CWE
CWE-295
Improper Certificate Validation
