{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/vendors/kube-logging/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["logging-operator (\u003c 0.0.0-20260608145523-cf437d7f1e05)"],"_cs_severities":["critical"],"_cs_tags":["remote-code-execution","kubernetes","configuration-injection","cve-2026-54680"],"_cs_type":"advisory","_cs_vendors":["kube-logging"],"content_html":"\u003cp\u003eThe Logging operator for Kubernetes, specifically versions prior to 0.0.0-20260608145523-cf437d7f1e05, contains a critical configuration injection vulnerability tracked as CVE-2026-54680. The operator is responsible for rendering Fluentd configuration files based on custom resource definitions (CRDs) such as 'Flow'. The 'FluentRender' logic fails to escape newline characters and special formatting characters when processing fields like 'record_transformer.records'.\u003c/p\u003e\n\u003cp\u003eAn attacker who has sufficient Kubernetes RBAC permissions to create or update 'Flow' resources in a namespace can inject arbitrary Fluentd configuration directives. By breaking out of the intended configuration context, an attacker can define a custom '\u0026lt;match **\u0026gt;' block utilizing the Fluentd '@type exec' plugin. This plugin allows for the execution of arbitrary shell commands within the Fluentd aggregator container. Given that the aggregator often manages logs across multiple tenants, this vulnerability facilitates lateral movement, potential access to sensitive node metadata via the Instance Metadata Service (IMDS), and full compromise of the logging infrastructure.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a target cluster running a vulnerable version of the Logging operator.\u003c/li\u003e\n\u003cli\u003eThe attacker gains or uses existing RBAC permissions to create a 'Flow' custom resource in a permitted namespace.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious 'record_transformer' entry containing newline characters designed to terminate the existing configuration block.\u003c/li\u003e\n\u003cli\u003eThe attacker injects a new '\u0026lt;match **\u0026gt;' block containing the '@type exec' plugin definition and a payload command.\u003c/li\u003e\n\u003cli\u003eThe Logging operator reconciles the 'Flow' resource and writes the malicious configuration to the generated Fluentd 'fluentd.conf' Secret.\u003c/li\u003e\n\u003cli\u003eThe Fluentd aggregator pod refreshes its configuration and initializes the injected 'out_exec' plugin.\u003c/li\u003e\n\u003cli\u003eA log message is triggered or emitted by a pod, forcing the Fluentd buffer to flush.\u003c/li\u003e\n\u003cli\u003eThe command specified in the 'command' parameter is executed with the privileges of the Fluentd aggregator process.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation results in arbitrary remote code execution within the Fluentd aggregator container. This allows the attacker to steal logs from all namespaces processed by the aggregator, exfiltrate sensitive data, or interact with cloud-native infrastructure services like IMDS (e.g., retrieving instance credentials). This vulnerability affects all environments where the Logging operator is deployed to manage multi-tenant log aggregation.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately upgrade the Logging operator to a version equal to or later than 0.0.0-20260608145523-cf437d7f1e05 to remediate CVE-2026-54680.\u003c/li\u003e\n\u003cli\u003eAudit Kubernetes RBAC policies to ensure that only authorized service accounts or users have the ability to create or modify 'Flow' and 'Output' custom resources within namespaces.\u003c/li\u003e\n\u003cli\u003eImplement Admission Control (e.g., OPA Gatekeeper or Kyverno) to validate 'Flow' resource contents, specifically looking for disallowed characters like newlines or unauthorized Fluentd plugin types within the 'record_transformer' fields.\u003c/li\u003e\n\u003cli\u003eReview logs for the creation of 'Flow' or 'Output' resources by unexpected users or ServiceAccounts using Kubernetes audit logs.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-29T17:02:01Z","date_published":"2026-07-29T17:02:01Z","id":"https://feed.craftedsignal.io/briefs/2026-07-logging-operator-rce/","summary":"The Logging operator is vulnerable to remote code execution due to improper input sanitization in Fluentd configuration rendering, allowing authenticated users to inject arbitrary configuration blocks via CRDs.","title":"Logging Operator Configuration Injection Leading to RCE","url":"https://feed.craftedsignal.io/briefs/2026-07-logging-operator-rce/"}],"language":"en","title":"CraftedSignal Threat Feed - Kube-Logging","version":"https://jsonfeed.org/version/1.1"}