{"id":"UBUNTU-CVE-2019-9517","details":"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.","modified":"2026-04-22T12:24:13.804451Z","published":"2019-08-13T00:00:00Z","related":["USN-4113-1"],"upstream":["CVE-2019-9517"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2019-9517"},{"type":"REPORT","url":"https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.md"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4113-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2019-9517"}],"affected":[{"package":{"name":"apache2","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/apache2@2.4.29-1ubuntu4.10?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.29-1ubuntu4.10"}]}],"versions":["2.4.27-2ubuntu3","2.4.29-1ubuntu1","2.4.29-1ubuntu2","2.4.29-1ubuntu3","2.4.29-1ubuntu4","2.4.29-1ubuntu4.1","2.4.29-1ubuntu4.2","2.4.29-1ubuntu4.3","2.4.29-1ubuntu4.4","2.4.29-1ubuntu4.5","2.4.29-1ubuntu4.6","2.4.29-1ubuntu4.7","2.4.29-1ubuntu4.8"],"ecosystem_specific":{"binaries":[{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2"},{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2-bin"},{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2-data"},{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2-suexec-custom"},{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2-suexec-pristine"},{"binary_version":"2.4.29-1ubuntu4.10","binary_name":"apache2-utils"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2019/UBUNTU-CVE-2019-9517.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}