|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.|
|Source||CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)|
Vulnerable and fixed packages
The table below lists information on source packages.
|apache2 (PTS)||stretch (security), stretch||2.4.25-3+deb9u9||fixed|
|buster, buster (security)||2.4.38-3+deb10u4||fixed|
The information below is based on the following data on fixed versions.
[jessie] - apache2 <not-affected> (HTTP/2 support only available since version 2.4.17 and later)
Affects upstream versions 2.4.20 to 2.4.39