{"id":"CVE-2026-40557","state":"PUBLISHED","title":"Apache Storm Prometheus Reporter: Disabling TLS verification for Prometheus Reporter also disables it for all other connections","description":"Improper Certificate Validation via Global SSL Context Downgrade in Apache Storm Prometheus Reporter\n\n\nVersions Affected: from 2.6.3 to 2.8.6\n\n\nDescription: \n\nIn 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.\n\n\nThe 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.\n\n\n\n\nMitigation: 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.","publishedAt":"2026-04-27T13:12:11.118Z","updatedAt":"2026-04-30T15:21:01.170Z","severity":{"score":4.8,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","source":"CISA-ADP"},"assigner":"apache","products":["Apache Software Foundation Apache Storm Prometheus Reporter"],"affected":[{"vendor":"Apache Software Foundation","product":"Apache Storm Prometheus Reporter","packageName":"org.apache.storm:storm-metrics-prometheus","defaultStatus":"unaffected","versions":[{"version":"2.6.3","status":"affected","lessThan":"2.8.7","versionType":"semver"}],"collectionURL":"https://repo.maven.apache.org/maven2/"}],"references":["https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq","http://www.openwall.com/lists/oss-security/2026/04/25/2"],"weaknesses":["CWE-295"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40557.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40557","state":"PUBLISHED","datePublished":"2026-04-27T13:12:11.118Z","dateUpdated":"2026-04-30T15:21:01.170Z","assignerShortName":"apache","assignerOrgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateReserved":"2026-04-14T11:20:51.218Z"},"containers":{"cna":{"title":"Apache Storm Prometheus Reporter: Disabling TLS verification for Prometheus Reporter also disables it for all other connections","descriptions":[{"lang":"en","value":"Improper Certificate Validation via Global SSL Context Downgrade in Apache Storm Prometheus Reporter\n\n\nVersions Affected: from 2.6.3 to 2.8.6\n\n\nDescription: \n\nIn 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.\n\n\nThe 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.\n\n\n\n\nMitigation: 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."}],"affected":[{"vendor":"Apache Software Foundation","product":"Apache Storm Prometheus Reporter","packageName":"org.apache.storm:storm-metrics-prometheus","defaultStatus":"unaffected","versions":[{"version":"2.6.3","status":"affected","lessThan":"2.8.7","versionType":"semver"}],"collectionURL":"https://repo.maven.apache.org/maven2/"}],"references":[{"url":"https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq","tags":["vendor-advisory"]}],"metrics":[{"other":{"content":{"text":"moderate"},"type":"Textual description of severity"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-295","description":"CWE-295 Improper Certificate Validation","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"apache","orgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateUpdated":"2026-04-27T13:12:11.118Z"},"credits":[{"lang":"en","type":"finder","value":"K"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/04/25/2"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-04-27T13:36:44.872Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":4.8,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"HIGH","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-04-27T13:58:23.511144Z","id":"CVE-2026-40557","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-30T15:21:01.170Z"}}]}}}