Most loaders allow dynamically linked libraries also known as shared libraries. Code is designed and tested using a suite of shared libraries which are loaded at execution time. The process of linking and loading is outside the scope of the C++ standard.
C++ prevents data pointers to be reinterpreted as function pointers and vice versa. Reinterpreting a pointer via a void pointer or std::intptr_t to a pointer of different type is undefined behaviour (with very few defined exceptions of data pointers to pointer to its raw bytes).
To avoid the vulnerability or mitigate its ill effects, C++ software developers can:
Follow the avoidance mechanisms of ISO/IEC 24772-1 clause 6.48.5.
Rely on compiler warnings and reports from analysis tools to prevent reinterpreting a data pointer as function pointer or vice versa.