CVE-2023-47118 : Security Advisory and Response

A heap buffer overflow vulnerability was discovered in ClickHouse server, an open-source column-oriented database management system. Attackers could exploit this issue to crash the server process without the need for authentication. This CVE has a CVSS base score of 7, indicating a high severity threat.

Understanding CVE-2023-47118

ClickHouse server is impacted by a heap buffer overflow vulnerability in the T64 codec decompression process, which could be exploited remotely without requiring authentication.

What is CVE-2023-47118?

The heap buffer overflow vulnerability in ClickHouse server allows attackers to send a specially crafted payload to trigger a bug in the T64 codec decompression logic, leading to a server crash.

The Impact of CVE-2023-47118

The vulnerability has a CVSS base score of 7, indicating a high severity threat. Attackers can exploit this issue remotely to disrupt ClickHouse server processes.

Technical Details of CVE-2023-47118

The vulnerability arises from a flaw in the ClickHouse server's decompression logic when processing T64 codec data, enabling heap buffer overflow attacks.

Vulnerability Description

An attacker can exploit this flaw by sending malicious payloads through the native interface on port 9000/tcp, triggering the heap buffer overflow and crashing the ClickHouse server.

Affected Systems and Versions

ClickHouse versions prior to 23.3.16.7-lts are impacted by this vulnerability. Updates to versions 23.10.2.13-stable, 23.9.4.11-stable, 23.8.6.16-lts, and later have addressed this issue.

Exploitation Mechanism

The vulnerability can be exploited by sending a crafted payload to the server's native interface, resulting in the heap buffer overflow through the T64 codec decompression logic.

Mitigation and Prevention

To address CVE-2023-47118, immediate mitigation steps are crucial to prevent potential exploitation and mitigate risks in the long term.

Immediate Steps to Take

Update impacted ClickHouse instances to versions 23.10.2.13-stable, 23.9.4.11-stable, 23.8.6.16-lts, or newer to mitigate the risk of heap buffer overflow attacks.

Long-Term Security Practices

Implement network controls, access restrictions, and ongoing monitoring to enhance the security posture of ClickHouse deployments and prevent future vulnerabilities.

Patching and Updates

Regularly apply security patches and updates provided by ClickHouse to address known vulnerabilities and protect the server environment from potential exploits.