CVE-2021-42388

CVE-2021-42388 is a high-severity heap out-of-bounds read vulnerability affecting ClickHouse database software, including its Debian Linux distributions. An authenticated attacker can trigger this flaw by submitting a specially crafted malicious query, exploiting a weakness in the LZ4 decompression process. This can lead to high confidentiality and availability impacts, potentially allowing an attacker to read sensitive data or cause a denial of service. Currently, there is no public exploit code available, nor is there evidence of active exploitation or significant community discussion surrounding this vulnerability.