Provide references for CVE-2021-33913.
Where can I find more information about CVE-2021-33913?
References are available at: https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220b, https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosure, https://lists.debian.org/debian-lts-announce/2022/01/msg00015.html, https://security.gentoo.org/glsa/202401-22.