wolfSSL Heap Overflow Vulnerability in TLS 1.3 ECH Parsing

A heap overflow vulnerability has been identified in wolfSSL's implementation of TLS 1.3, specifically in the parsing of the Encrypted Client Hello (ECH) extension. This vulnerability arises from an integer underflow in the ECH extension parsing logic, which leads to a buffer length calculation error. As a result, data can be written beyond the limits of an allocated buffer, creating a potential security risk. It is important to note that ECH is disabled by default in wolfSSL, and the ECH standard is still being developed.

Impact

Exploitation of this vulnerability leads to a heap overflow, which can commonly result in arbitrary code execution or memory corruption.