Fixes the following security vulnerabilities:
- CVE-2019-9511 "Data Dribble": The attacker requests a large amount of data
from a specified resource over multiple streams. They manipulate window
size and stream priority to force the server to queue the data in 1-byte
chunks. Depending on how efficiently this data is queued, this can
consume excess CPU, memory, or both, potentially leading to a denial of
service.
- CVE-2019-9512 "Ping Flood": The attacker sends continual pings to an
HTTP/2 peer, causing the peer to build an internal queue of responses.
Depending on how efficiently this data is queued, this can consume excess
CPU, memory, or both, potentially leading to a denial of service.
- CVE-2019-9513 "Resource Loop": The attacker creates multiple request
streams and continually shuffles the priority of the streams in a way that
causes substantial churn to the priority tree. This can consume excess
CPU, potentially leading to a denial of service.
- CVE-2019-9514 "Reset Flood": The attacker opens a number of streams and
sends an invalid request over each stream that should solicit a stream of
RST_STREAM frames from the peer. Depending on how the peer queues the
RST_STREAM frames, this can consume excess memory, CPU, or both,
potentially leading to a denial of service.
- CVE-2019-9515 "Settings Flood": The attacker sends a stream of SETTINGS
frames to the peer. Since the RFC requires that the peer reply with one
acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost
equivalent in behavior to a ping. Depending on how efficiently this data
is queued, this can consume excess CPU, memory, or both, potentially
leading to a denial of service.
- CVE-2019-9516 "0-Length Headers Leak": The attacker sends a stream of
headers with a 0-length header name and 0-length header value, optionally
Huffman encoded into 1-byte or greater headers. Some implementations
allocate memory for these headers and keep the allocation alive until the
session dies. This can consume excess memory, potentially leading to a
denial of service.
- CVE-2019-9517 "Internal Data Buffering": 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, potentially leading to a denial
of service.
- CVE-2019-9518 "Empty Frames Flood": The attacker sends a stream of frames
with an empty payload and without the end-of-stream flag. These frames
can be DATA, HEADERS, CONTINUATION and/or PUSH_PROMISE. The peer spends
time processing each frame disproportionate to attack bandwidth. This can
consume excess CPU, potentially leading to a denial of service.
(Discovered by Piotr Sikora of Google)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
b775c99262