VULNERABILITY INTELLIGENCE

CVE-2019-9517

CVSS score7.5 HIGH
EPSS probability27.89%
CISA KEVNot currently listed
Published2019-08-13
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Weakness classification

  • CWE-400: Uncontrolled Resource Consumption
  • CWE-770: Allocation of Resources Without Limits or Throttling

Primary references