LuaTeX before 1.17.0 allows execution of arbitrary shell commands when compiling a TeX file obtained from an untrusted source. This occurs because luatex-core.lua lets the original io.popen be accessed. This also affects TeX Live before 2023 r66984 and MiKTeX before 23.5.
https://tug.org/~mseven/luatex.html
https://tug.org/pipermail/tex-live/2023-May/049188.html
https://gitlab.lisn.upsaclay.fr/texlive/luatex/-/tags/1.17.0
https://github.com/TeX-Live/texlive-source/releases/tag/build-svn66984