Skip to content
Fencer Vulns
medium 5.3

CVE-2024-30255 json

HTTP/2: CPU exhaustion due to CONTINUATION frame flood

published 2024-04-04 2 y ago modified 2026-09-08 2 mo ago also BIT-envoy-2024-30255 , EUVD-2024-28182 , GHSA-j654-3ccm-vfmm

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
85.0%
EPSS 85.0% chance of exploitation in 30 days, percentile 99.7%
public exploits
0
none known

Summary

Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustion due to flood of CONTINUATION frames. Envoy's HTTP/2 codec allows the client to send an unlimited number of CONTINUATION frames even after exceeding Envoy's header map limits. This allows an attacker to send a sequence of CONTINUATION frames without the END_HEADERS bit set causing CPU utilization, consuming approximately 1 core per 300Mbit/s of traffic and culminating in denial of service through CPU exhaustion. Users should upgrade to version 1.29.3, 1.28.2, 1.27.4, or 1.26.8 to mitigate the effects of the CONTINUATION flood. As a workaround, disable HTTP/2 protocol for downstream connections.

Patch / fix

  • bitnami envoy 1.26.8, 1.27.4, 1.28.2, 1.29.3
  • envoyproxy envoy 1.26.8, 1.27.4, 1.28.2, 1.29.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-30255 updated cvss 5.3

envoy: HTTP/2 CPU exhaustion due to CONTINUATION frame flood

  • Red Hat Custom Metric Autoscaler operator for Red Hat Openshift custom-metrics-autoscaler/custom-metrics-autoscaler-rhel8
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel9
    affected: workaround, no fix available “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat Migration Toolkit for Applications 6 mta/mta-hub-rhel8 Red Hat OpenShift Serverless openshift-serverless-1/eventing-mtping-rhel8 Red Hat Ceph Storage 6 rhceph/rhceph-6-dashboard-rhel9
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat OpenShift Container Platform 4 openshift-selinuxd-container, openshift4/ose-contour-rhel8
    affected: workaround, no fix available, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat Openshift Container Storage 4 ocs4/cephcsi-rhel8
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat OpenShift Data Science (RHODS) rhods/odh-operator-base-rhel8, rhods/odh-ml-pipelines-cache-rhel8
    affected: workaround, no fix available “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat OpenShift Dev Spaces devspaces/devspaces-rhel8-operator Red Hat OpenShift distributed tracing 2 rhosdt/tempo-gateway-rhel8 Red Hat OpenShift distributed tracing 3 rhosdt/opentelemetry-rhel8-operator
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • Red Hat Openshift Sandboxed Containers openshift-sandboxed-containers/osc-rhel8-operator
    affected: workaround, no fix available “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
show 5 more
  • Red Hat Ceph Storage 5.3 Tools rhceph/rhceph-5-rhel8 5-535, rhceph/keepalived-rhel8 2.1.5-44, rhceph/snmp-notifier-rhel8 1.2.1-88, rhceph/rhceph-5-dashboard-rhel8 5-97, rhceph/rhceph-haproxy-rhel8 2.2.19-45
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHBA-2025:1479
  • Red Hat Ceph Storage 7.1 Tools rhceph/rhceph-7-rhel9 7-493, rhceph/ceph-nvmeof-cli-rhel9 1.2.19-1, rhceph/grafana-rhel9 10.4.8-1740412443, rhceph/rhceph-promtail-rhel9 v3.0.0-14, rhceph/keepalived-rhel9 2.2.8-1740412056, rhceph/snmp-notifier-rhel9 1.2.1-1740411201, +1 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHBA-2025:1772
  • Red Hat Migration Toolkit 1.7 rhmtc/openshift-migration-velero-plugin-for-gcp-rhel8 v1.7.16-6
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4520
  • Red Hat RHOSSM 2.5 for RHEL 8 openshift-service-mesh/pilot-rhel8 2.5.5-4, openshift-service-mesh/grafana-rhel8 2.5.5-3, openshift-service-mesh/kiali-rhel8 1.73.15-3, openshift-service-mesh/proxyv2-rhel8 2.5.5-6, openshift-service-mesh/istio-cni-rhel8 2.5.5-4, openshift-service-mesh/ratelimit-rhel8 2.5.5-3, +2 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:7725
  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/logging-loki-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel8, oadp/oadp-velero-plugin-for-gcp-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/acm-grafana-rhel8, rhacm2/management-ingress-rhel8 Red Hat Migration Toolkit 1.7 rhmtc/openshift-migration-ui-rhel8 v1.7.16-6, rhmtc/openshift-velero-plugin-rhel8 v1.7.16-5, rhmtc/openshift-migration-velero-rhel8 v1.7.16-4, rhmtc/openshift-migration-openvpn-rhel8 v1.7.16-6, rhmtc/openshift-migration-registry-rhel8 v1.7.16-5, rhmtc/openshift-migration-rhel8-operator v1.7.16-6, +10 more Red Hat OpenShift Container Platform 4 openshift4/ose-prometheus Red Hat Openshift Data Foundation 4 odf4/odf-topolvm-rhel8
    +1 more products
    Red Hat OpenStack Platform 16.2 osp-director-provisioner-container
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

85.02% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami envoy
<1.26.8
>=1.27.0, <1.27.4
>=1.28.0, <1.28.2
>=1.29.0, <1.29.3
1.26.8
1.27.4
1.28.2
1.29.3

Affected products

  • envoyproxy envoy

Classification

Weakness
  • CWE-390 Detection of Error Condition Without Action

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.