It is possible to crash or redirect the execution flow of the ClickHouse server process from an unauthenticated vector by sending a specially crafted request to the ClickHouse server native interface. This redirection is limited to what is available within a 256-byte range of memory at the time of execution, and no known remote code execution (RCE) code has been produced or exploited. Fixes have been merged to all currently supported version of ClickHouse. If you are maintaining your own forked version of ClickHouse or using an older version and cannot upgrade, the fix for this vulnerability can be found in this commit https://github.com/ClickHouse/ClickHouse/pull/64024 .
Workaround:
A 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().