Description
Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.
Remediation
References
Related Vulnerabilities
PostgreSQL Improper Authentication Vulnerability (CVE-2007-6601)
WordPress Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2017-5487)
PHP Improper Input Validation Vulnerability (CVE-2020-7071)
Liferay DXP Cleartext Storage of Sensitive Information Vulnerability (CVE-2021-33325)