Wordpress is an open source CMS. A user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks. This requires WordPress installation to be using PHP 8. Access to internal files is possible in a successful XXE attack. This has been patched in WordPress version 5.7.1, along with the older affected versions via a minor release. We strongly recommend you keep auto-updates enabled.
https://www.debian.org/security/2021/dsa-4896
https://lists.debian.org/debian-lts-announce/2021/04/msg00017.html
https://github.com/WordPress/wordpress-develop/security/advisories/GHSA-rv47-pc52-qrhh
https://github.com/Kashyapghodasara/Public_Exploit-1--Wordpress-CVE-2021-29447
https://github.com/KovuuBzhh/recon-tool
https://github.com/Justin-Saji/Syntecxhub_Vulnerability-CVE-Scanner
https://github.com/phantom-offensive/AppAssault
https://github.com/phantom-offensive/AppAssaultLab
https://github.com/Phantom-C2-77/AppAssaultLab
https://github.com/danilo1992-sys/CVE-2021-29447
https://github.com/C0DE33301/My-CVE-Notes
https://github.com/0xricksanchez/CVE-2021-29447
https://github.com/specializzazione-cyber-security/demo-CVE-2021-29447-lezione
https://github.com/thomas-osgood/CVE-2021-29447
https://github.com/motikan2010/CVE-2021-29447
https://wordpress.org/news/category/security/
https://blog.sonarsource.com/wordpress-xxe-security-vulnerability/
http://packetstormsecurity.com/files/164198/WordPress-5.7-Media-Library-XML-Injection.html