CVE-2020-9491 in NiFi
Summary
by MITRE • 10/04/2020
In Apache NiFi 1.2.0 to 1.11.4, the NiFi UI and API were protected by mandating TLS v1.2, as well as listening connections established by processors like ListenHTTP, HandleHttpRequest, etc. However intracluster communication such as cluster request replication, Site-to-Site, and load balanced queues continued to support TLS v1.0 or v1.1.
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Analysis
by VulDB Data Team • 11/15/2020
Apache NiFi versions 1.2.0 through 1.11.4 contained a significant security vulnerability where the user interface and api endpoints were properly secured with tls v1.2 requirements, yet internal cluster communications remained vulnerable due to continued support for older tls versions. This inconsistency created a potential attack vector where adversaries could exploit the weaker tls protocols used for cluster replication, site-to-site communication, and load balanced queue operations while the external interfaces remained protected. The vulnerability stems from the fact that tls v1.0 and v1.1 protocols contain known cryptographic weaknesses that have been deprecated by industry standards and are susceptible to various attacks including man-in-the-middle and protocol downgrade attacks. This issue represents a classic case of incomplete security implementation where external-facing components receive proper protection while internal communication channels remain exposed to known vulnerabilities. The flaw aligns with cwe-319, which addresses the exposure of sensitive information through improper use of cryptographic protocols, and falls under the broader category of insecure communication protocols that have been extensively documented in nist cybersecurity framework guidelines. Attackers could potentially leverage this vulnerability to intercept and manipulate cluster communications, potentially leading to unauthorized access to internal data flows and compromising the integrity of the entire nifi cluster. The impact extends beyond simple data interception as it could enable attackers to manipulate cluster state information, disrupt replication processes, and potentially gain unauthorized access to sensitive processing flows that operate within the cluster environment. Organizations utilizing these affected versions should prioritize immediate remediation by upgrading to patched versions that enforce tls v1.2 across all communication channels, including internal cluster operations. The mitigation strategy should also include comprehensive network segmentation and monitoring of cluster communications to detect any potential exploitation attempts. Additionally, implementing proper certificate management practices and ensuring all cluster nodes maintain consistent security configurations will help prevent similar issues in the future. This vulnerability demonstrates the critical importance of maintaining consistent security policies across all communication channels within distributed systems, as highlighted in the mitre att&ck framework under the privilege escalation and credential access domains where weakened internal communications can serve as entry points for broader system compromise. The vulnerability also underscores the necessity of following secure coding practices and security by design principles, where security controls are applied consistently across all system components rather than selectively protecting only external interfaces. Organizations should conduct thorough security assessments to identify similar inconsistencies in other distributed systems and ensure that all internal communication channels maintain the same security standards as external-facing components.