cbcvebase.
CVE-2019-9514
published 2019-08-13

CVE-2019-9514: Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service. The attacker opens a number of streams and sends an…

PriorityP358high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
82.81%
99.6th percentile
Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service. 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.

Affected

75 ranges· showing 25
VendorProductVersion rangeFixed in
apachetraffic_server6.0.0 – 6.2.3
apachetraffic_server7.0.0 – 7.1.6
apachetraffic_server8.0.0 – 8.0.3
appleswiftnio1.0.0 – 1.4.0
appleswiftnio_http_2
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
debiandebian_linux
debiandebian_linux
debianh2o< h2o 2.2.5+dfsg2-3 (bookworm)h2o 2.2.5+dfsg2-3 (bookworm)
debiannodejs< h2o 2.2.5+dfsg2-3 (bookworm)h2o 2.2.5+dfsg2-3 (bookworm)
debianrust-h2< h2o 2.2.5+dfsg2-3 (bookworm)h2o 2.2.5+dfsg2-3 (bookworm)
debiantrafficserver< h2o 2.2.5+dfsg2-3 (bookworm)h2o 2.2.5+dfsg2-3 (bookworm)
f5big-ip_local_traffic_manager>= 11.6.1 < 11.6.5.111.6.5.1
f5big-ip_local_traffic_manager>= 12.1.0 < 12.1.5.112.1.5.1
f5big-ip_local_traffic_manager>= 13.1.0 < 13.1.3.213.1.3.2
f5big-ip_local_traffic_manager>= 14.0.0 < 14.0.1.114.0.1.1
f5big-ip_local_traffic_manager>= 14.1.0 < 14.1.2.114.1.2.1
f5big-ip_local_traffic_manager>= 15.0.0 < 15.0.1.115.0.1.1
fedoraprojectfedora
fedoraprojectfedora
golang.orgx_net>= 0 < 0.0.0-20190813141303-74dc4d7220e70.0.0-20190813141303-74dc4d7220e7
h2oh2o>= 0 < 2.2.5+dfsg2-32.2.5+dfsg2-3
h2oh2o>= 0 < 2.2.5+dfsg2-32.2.5+dfsg2-3

Detection & IOCsextracted from sources · hover to see the quote

registryHKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters
registryHKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\Http2MaxServerResetsPerMinute
registryHKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\Http2MaxResetsPerStream
registryHKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\EnableHttp2TIs
registryHKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\EnableHttp2Cleartext
snort
alert tcp-pkt any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET DOS Possible Microsoft Windows HTTP2 Reset Flood Denial of Service Inbound (CVE-2019-9514)"; flow:established,to_server; dsize:9; content:"|00 00 00 01 04 00 00 00|"; startswith; fast_pattern; threshold:type threshold, count 45, seconds 60, track by_src; reference:cve,2019-9514; classtype:denial-of-service; sid:2034093; rev:1; metadata:attack_target Server, created_at 2021_10_04, cve CVE_2019_9514, deployment Perimeter, deployment Internal, confidence Medium, signature_severity Major, tag Exploit, updated_at 2021_10_04, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)
bytes
|00 00 00 01 04 00 00 00|
  • Detect HTTP/2 RST_STREAM reset flood: match TCP payload of exactly 9 bytes starting with the byte sequence |00 00 00 01 04 00 00 00|, threshold 45 occurrences per 60 seconds per source IP, inbound to servers.
  • The attack pattern involves opening many HTTP/2 streams and sending invalid requests to elicit RST_STREAM frames from the peer; monitor for abnormally high RST_STREAM frame rates from a single client.
  • On Windows IIS/HTTP.sys, monitor registry key HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters for the presence or modification of Http2MaxServerResetsPerMinute, Http2MaxResetsPerStream, and related HTTP/2 throttle values, which are added by the patch and left unconfigured by default.
  • A HTTP/2 server experiencing this attack may show unbounded memory or CPU growth; correlate with high RST_STREAM or HEADERS frame counts using HEADERS frames with invalid HTTP headers.
  • ·On Windows, the HTTP/2 throttling registry values (Http2MaxServerResetsPerMinute, Http2MaxResetsPerStream, Http2MaxPingsPerMinute, etc.) are added by the patch but are OFF by default; administrators must explicitly configure them to be protected.
  • ·The Snort/ET rule threshold (45 resets in 60 seconds per source) is a heuristic and may need tuning per environment to avoid false positives or missed detections.
  • ·golang and nodejs packages have no available mitigation at time of advisory; both packages require upstream fixes before patching is possible.

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv3.07.5HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.07.8HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
ghsa7.5HIGH
osv7.5HIGH
vendor_debian7.5HIGH
vendor_msrc7.5HIGH
vendor_redhat7.5HIGH
vendor_ubuntu7.5HIGH
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