Unauthenticated denial-of-service via BEAM atom table exhaustion in membrane_mp4_plugin

Summary

Allocation of Resources Without Limits or Throttling vulnerability in membraneframework membrane_mp4_plugin allows unauthenticated denial-of-service via BEAM atom table exhaustion. The MP4 box header parser converts each 4-byte box name to an atom using String.to_atom/1 without validation. 'Elixir.Membrane.MP4.Container.Header':parse_box_name/1 in lib/membrane_mp4/container/header.ex interns every box name encountered while 'Elixir.Membrane.MP4.Container.Header':parse/1 walks the input. BEAM atoms are never garbage-collected, so each unique attacker-controlled 4-byte name is a permanent allocation. A crafted MP4 of approximately 8 MB containing roughly 1.1 million boxes with distinct non-standard names exhausts the atom table (default ceiling around 1,048,576 atoms), aborting the entire BEAM node and taking down all applications running on it. This issue affects membrane_mp4_plugin from 0.3.0 before 0.36.7.