CVE-2021-23017 – Nginx 1.20.0 - Denial of Service (DOS)

https://notcve.org/view.php?id=CVE-2021-23017

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact. Se identificó un problema de seguridad en el solucionador de nginx, que podría permitir a un atacante que pueda falsificar paquetes UDP desde el servidor DNS para causar una sobrescritura de memoria de 1 byte, lo que causaría un bloqueo del proceso de trabajo u otro impacto potencial A flaw was found in nginx. An off-by-one error while processing DNS responses allows a network attacker to write a dot character out of bounds in a heap allocated buffer which can allow overwriting the least significant byte of next heap chunk metadata likely leading to a remote code execution in certain circumstances. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. Nginx version 1.20.0 suffers from a denial of service vulnerability. • https://www.exploit-db.com/exploits/50973 https://github.com/M507/CVE-2021-23017-PoC https://github.com/ShivamDey/CVE-2021-23017 https://github.com/lakshit1212/CVE-2021-23017-PoC http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html https://lists.apache.org/thread.html/r37e6b2165f7c910d8e15fd54f4697857619ad2625f56583802004009%40%3Cnotifications.apisix.apache.org%3E https://lists.apache.org/thread.html/r4d4966221ca399 • CWE-193: Off-by-one Error •