CVE-2021-23218 in Container Runtime
Summary
by MITRE • 01/10/2022
When running with FIPS mode enabled, Mirantis Container Runtime 20.10.8 leaks memory during TLS Handshakes which could be abused to cause a denial of service.
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Analysis
by VulDB Data Team • 01/13/2022
The vulnerability identified as CVE-2021-23218 affects Mirantis Container Runtime version 20.10.8 when operating in FIPS mode, presenting a memory leak condition during TLS handshake operations that can be exploited for denial of service attacks. This issue specifically manifests when the container runtime engine processes secure communication protocols under Federal Information Processing Standards compliance requirements, creating a scenario where allocated memory resources are not properly released during the cryptographic handshake process.
The technical flaw stems from improper memory management within the TLS implementation of the container runtime engine when FIPS mode is active. During the TLS handshake procedure, the system allocates memory structures to handle cryptographic operations and key exchanges, but fails to correctly deallocate these resources upon completion of the handshake process. This memory leak occurs repeatedly with each TLS connection attempt, gradually consuming available system memory resources and potentially leading to system instability or complete service unavailability. The vulnerability is particularly concerning because it operates within the core security infrastructure of the container runtime, making it difficult to detect and address without specific monitoring tools.
The operational impact of this vulnerability extends beyond simple resource exhaustion, as it can disrupt containerized application environments that rely on secure communication channels. When multiple containers or applications attempt to establish TLS connections simultaneously, the memory leak accelerates, potentially causing the host system to become unresponsive or crash entirely. This affects not only the container runtime itself but also the entire container orchestration environment, as the compromised system may fail to maintain proper service availability for dependent applications. The vulnerability is especially dangerous in production environments where high availability and security compliance are critical requirements.
Mitigation strategies should focus on immediate patching of the affected Mirantis Container Runtime version to address the memory management issue within the FIPS-enabled TLS implementation. Organizations should also implement monitoring solutions that track memory usage patterns during TLS handshake operations to detect potential exploitation attempts. Additionally, system administrators should consider temporarily disabling FIPS mode if the memory leak cannot be immediately resolved through patching, while maintaining alternative security measures. The vulnerability aligns with CWE-401, which addresses improper deallocation of memory, and can be categorized under ATT&CK technique T1499.004 for endpoint denial of service, as it specifically targets system resource exhaustion through memory leaks in security-critical components.
Security teams should conduct comprehensive assessments of their containerized environments to identify systems running affected versions of Mirantis Container Runtime, particularly those configured with FIPS compliance requirements. Regular security audits should include verification of memory management practices in cryptographic implementations, with specific attention to FIPS-enabled configurations that may expose similar vulnerabilities. The incident highlights the importance of thorough testing of security compliance features in container runtimes, as FIPS mode implementations can introduce unexpected operational issues that may not surface during normal usage patterns. Organizations should also maintain updated incident response procedures that account for memory leak vulnerabilities in cryptographic components, ensuring rapid identification and remediation of similar issues that may arise in other security-critical systems.