z3usx01/cve-2021-23017-pocThe issue only affects nginx if the "resolver" directive is used in the configuration file. Further, the attack is only possible if an attacker is able to forge UDP packets from the DNS server.
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. The issue only affects nginx if the "resolver" directive is used in the configuration file. Further, the attack is only possible if an attacker is able to forge UDP packets from the DNS server.
