CVE-2022-44011 in ClickHouse
Summary
by MITRE • 11/23/2023
An issue was discovered in ClickHouse before 22.9.1.2603. An authenticated user (with the ability to load data) could cause a heap buffer overflow and crash the server by inserting a malformed CapnProto object. The fixed versions are 22.9.1.2603, 22.8.2.11, 22.7.4.16, 22.6.6.16, and 22.3.12.19.
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Analysis
by VulDB Data Team • 12/16/2023
The vulnerability CVE-2022-44011 represents a critical heap buffer overflow condition affecting the ClickHouse database management system prior to version 22.9.1.2603. This issue specifically targets the CapnProto serialization format processing within the database engine, creating a scenario where authenticated users with data loading privileges can exploit the system through carefully crafted malformed objects. The vulnerability falls under the category of memory safety issues and demonstrates a fundamental flaw in input validation and memory management within the database's serialization layer.
The technical flaw manifests when the ClickHouse server processes CapnProto objects during data insertion operations. When an authenticated user submits malformed CapnProto data, the system fails to properly validate the object boundaries before attempting to deserialize and store the information in heap memory. This inadequate boundary checking allows the attacker to write beyond the allocated memory buffer, causing a heap buffer overflow condition that ultimately leads to server crash and potential denial of service. The vulnerability is classified as a heap-based buffer overflow under CWE-121 and represents a classic memory corruption flaw that can be leveraged for system instability.
The operational impact of this vulnerability extends beyond simple service disruption, as it provides an authenticated attacker with the capability to cause persistent denial of service against the ClickHouse server. Since the attack requires only the ability to load data into the system, any user with appropriate permissions can potentially exploit this weakness, making it particularly dangerous in multi-user environments where privilege escalation might be possible. The crash condition affects the entire server process, requiring manual intervention for recovery and potentially allowing for extended downtime in production environments. This vulnerability aligns with ATT&CK technique T1499.004 for network denial of service and represents a significant risk to database availability.
Organizations using ClickHouse versions prior to the patched releases should immediately implement mitigation strategies including upgrading to the fixed versions 22.9.1.2603, 22.8.2.11, 22.7.4.16, 22.6.6.16, and 22.3.12.19. Additionally, network segmentation and access controls should be enforced to limit data loading privileges to only trusted users and processes. Monitoring should be implemented to detect unusual data loading patterns that might indicate exploitation attempts, while regular security audits should verify that all ClickHouse instances have been properly updated. The vulnerability serves as a reminder of the importance of proper input validation and memory safety practices in database systems, particularly those handling complex serialization formats like CapnProto.