CVE-2021-43305: clickhouse Heap-based Buffer Overflow

Vulnerability summary

CVE-2021-43305 is a high (CVSS 8.8) Heap-based Buffer Overflow vulnerability in clickhouse. EPSS estimates a 1.67% chance of exploitation in the next 30 days, higher than 76.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 14-03-2022
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

Heap buffer overflow in Clickhouse's LZ4 compression codec when parsing a malicious query. There is no verification that the copy operations in the LZ4::decompressImpl loop and especially the arbitrary copy operation wildCopy<copy_amount>(op, ip, copy_end), don’t exceed the destination buffer’s limits. This issue is very similar to CVE-2021-43304, but the vulnerable copy operation is in a different wildCopy call.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.