CVE-2021-22884: Input Validation

Affected Node.js versions are vulnerable to denial of service attacks when the whitelist includes “localhost6”. When “localhost6” is not present in /etc/hosts, it is just an ordinary domain that is resolved via DNS, i.e., over network. If the attacker controls the victim's DNS server or can spoof its responses, the DNS rebinding protection can be bypassed by using the “localhost6” domain. As long as the attacker uses the “localhost6” domain, they can still apply the attack described in CVE-2018-7160.

Reference: https://nodejs.org/en/blog/vulnerability/february-2021-security-releases/#update-23-feb-2021-security-releases-available

— Red Hat

Node.js before 10.24.0, 12.21.0, 14.16.0, and 15.10.0 is vulnerable to DNS rebinding attacks as the whitelist includes “localhost6”. When “localhost6” is not present in /etc/hosts, it is just an ordinary domain that is resolved via DNS, i.e., over network. If the attacker controls the victim's DNS server or can spoof its responses, the DNS rebinding protection can be bypassed by using the “localhost6” domain. As long as the attacker uses the “localhost6” domain, they can still apply the attack described in CVE-2018-7160.

Node.js is vulnerable to a denial of service, caused by an error when the allowlist includes "localhost6". By controlling the victim's DNS server or spoofing its responses, an attacker could exploit this vulnerability to bypass the DNS rebinding protection mechanism using the "localhost6" domain and cause a denial of service.

— IBM