Bug 2291274 (CVE-2024-36405)

A flaw was found in liboqs, a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. A control-flow timing lean issue has been identified in the reference implementation of the Kyber key encapsulation mechanism when it is compiled with Clang 15-18 for `-Os`, `-O1`, and other compilation options. A proof-of-concept local attack on the reference implementation leaks the entire ML-KEM 512 secret key in ~10 minutes using end-to-end decapsulation timing measurements. The issue has been fixed in version 0.10.1. As a possible workaround, some compiler options may produce vectorized code that does not leak secret information. However, relying on these compiler options as a workaround may not be reliable.