Insufficient sanitisation in the OCaml compiler versions 4.04.0 and 4.04.1 allows external code to be executed with raised privilege in binaries marked as setuid, by setting the CAML_CPLUGINS, CAML_NATIVE_CPLUGINS, or CAML_BYTE_CPLUGINS environment variable.
https://sympa.inria.fr/sympa/arc/caml-list/2017-06/msg00094.html
https://security.gentoo.org/glsa/201710-07