CVE-2021-4047 in OpenShift
Summary
by MITRE • 04/12/2022
The release of OpenShift 4.9.6 included four CVE fixes for the haproxy package, however the patch for CVE-2021-39242 was missing. This issue only affects Red Hat OpenShift 4.9.
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Analysis
by VulDB Data Team • 04/14/2022
The vulnerability described in CVE-2021-4047 represents a critical oversight in the security patching process for Red Hat OpenShift 4.9.6 releases, specifically concerning the haproxy package that serves as a fundamental load balancing and proxy component within the OpenShift platform. This issue demonstrates the complex nature of containerized orchestration environments where multiple security patches must be carefully coordinated across various system components. The haproxy package forms a crucial part of the OpenShift networking stack, handling traffic routing and load distribution for applications deployed within the platform. The missing patch for CVE-2021-39242 within the OpenShift 4.9.6 release creates a persistent security gap that could potentially allow attackers to exploit weaknesses in the proxy functionality. This vulnerability directly impacts the integrity and security posture of OpenShift clusters running version 4.9, as it leaves the platform exposed to attacks that could compromise the underlying proxy infrastructure.
The technical flaw stems from the incomplete patching of CVE-2021-39242 within the haproxy component of OpenShift 4.9.6, where the specific vulnerability in the haproxy package was not addressed despite other related CVEs being resolved in the same release. This represents a failure in the security validation process during the release cycle, where comprehensive testing and verification of all applied patches may not have been performed adequately. The haproxy package vulnerability likely involves issues related to memory handling, input validation, or proxy processing that could allow for denial of service conditions or potentially arbitrary code execution. The missing patch creates an environment where attackers could exploit the specific weakness in the haproxy implementation, potentially affecting traffic routing, service availability, or data integrity within the OpenShift cluster. This situation highlights the importance of thorough patch validation and the potential risks associated with partial security updates in complex enterprise environments.
The operational impact of this vulnerability extends beyond simple security concerns to potentially affect the reliability and availability of services running within OpenShift 4.9 clusters. Organizations using this specific version of OpenShift may experience increased risk of service disruption due to the unpatched proxy vulnerability, which could be exploited to cause denial of service conditions or compromise the security of traffic flowing through the platform. The vulnerability affects the core networking infrastructure of the platform, meaning that any application relying on haproxy for load balancing, SSL termination, or traffic routing could be exposed to potential attacks. This creates a significant risk for enterprises that depend on OpenShift for critical workloads, as the vulnerability could be leveraged to disrupt business operations or gain unauthorized access to sensitive data flowing through the proxy infrastructure. The impact is particularly concerning given that this issue is specific to OpenShift 4.9, suggesting that organizations using this version may be particularly vulnerable without proper mitigation measures.
Organizations affected by this vulnerability should implement immediate remediation strategies to address the missing patch for CVE-2021-39242 in their OpenShift 4.9 environments. The recommended approach involves upgrading to a newer OpenShift version that includes the complete set of security patches for the haproxy package, or applying the specific missing patch if available through Red Hat's security advisory channels. Security teams should conduct comprehensive assessments of their OpenShift clusters to identify any potential exploitation attempts and monitor network traffic for signs of attack activity targeting the haproxy component. The vulnerability aligns with CWE-119 which addresses memory safety issues, and may also relate to CWE-20 which covers input validation problems. From an ATT&CK perspective, this vulnerability could be leveraged as part of initial access or persistence phases, particularly through network-based attack vectors that target proxy infrastructure. Organizations should also implement network monitoring solutions to detect unusual traffic patterns that might indicate exploitation attempts against the unpatched haproxy component, ensuring that their security operations centers maintain visibility into proxy-related activities within their OpenShift environments.