# CVE-2024-30156: Denial of service in n/a > Attackers can exhaust HTTP/2 connection control flow windows in Varnish Cache, causing a denial of service. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 24 Mar 2024 - **Updated:** 21 Nov 2024 - **Also known as:** ALPINE-CVE-2024-30156, ALSA-2024:1690, ALSA-2024:1691, DEBIAN-CVE-2024-30156, GHSA-c3wj-m54r-wfgq, MGASA-2024-0124, OESA-2024-1415, RHSA-2024:1689, RHSA-2024:1690, RHSA-2024:1691, RHSA-2024:2700, RHSA-2024:2820, RHSA-2024:2938, RHSA-2024:3305, RHSA-2024:3426, RHSA-2024:4937, RLSA-2024:1690, RLSA-2024:1691, ROOT-OS-DEBIAN-12-CVE-2024-30156, UBUNTU-CVE-2024-30156 ## What is CVE-2024-30156? CVE-2024-30156 is a high-severity denial of service vulnerability in n/a, published on 24 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Varnish Cache before 7.3.2 and 7.4.x before 7.4.3 (and before 6.0.13 LTS), and Varnish Enterprise 6 before 6.0.12r6, allows credits exhaustion for an HTTP/2 connection control flow window, aka a Broke Window Attack. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling) ## Which versions are affected by CVE-2024-30156? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `varnish` | AlmaLinux:8 | All versions | 6.0.13-1.module_el8.9.0+3786+e8a73bbf.alma.1 | | `varnish-devel` | AlmaLinux:8 | All versions | 6.0.13-1.module_el8.9.0+3786+e8a73bbf.alma.1 | | `varnish-docs` | AlmaLinux:8 | All versions | 6.0.13-1.module_el8.9.0+3786+e8a73bbf.alma.1 | | `varnish-modules` | AlmaLinux:8 | All versions | 0.15.0-6.module_el8.5.0+2620+03a0c2cc | | `varnish-modules` | AlmaLinux:8 | All versions | 0.15.0-6.module_el8.5.0+76+a10ffa55 | | `varnish-modules` | AlmaLinux:8 | All versions | 0.15.0-6.module_el8.6.0+3089+dac88e97 | | `varnish` | AlmaLinux:9 | All versions | 6.6.2-4.el9_3.1 | | `varnish-devel` | AlmaLinux:9 | All versions | 6.6.2-4.el9_3.1 | | `varnish-docs` | AlmaLinux:9 | All versions | 6.6.2-4.el9_3.1 | | `varnish` | Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.13-1.module+el8.9.0+21617+7578fa11 | | `varnish-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.13-1.module+el8.9.0+21617+7578fa11 | | `varnish-docs` | Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.13-1.module+el8.9.0+21617+7578fa11 | | `varnish-modules` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-6.module+el8.9.0+21617+7578fa11 | | `varnish-modules-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-6.module+el8.9.0+21617+7578fa11 | | `varnish-modules-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-6.module+el8.9.0+21617+7578fa11 | | `varnish` | Red Hat:enterprise_linux:9::appstream | All versions | 0:6.6.2-4.el9_3.1 | | `varnish-docs` | Red Hat:enterprise_linux:9::appstream | All versions | 0:6.6.2-4.el9_3.1 | | `varnish-devel` | Red Hat:enterprise_linux:9::crb | All versions | 0:6.6.2-4.el9_3.1 | | `varnish` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:6.0.6-1.module+el8.2.0+22154+6b906702 | | `varnish-devel` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:6.0.6-1.module+el8.2.0+22154+6b906702 | | `varnish-docs` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:6.0.6-1.module+el8.2.0+22154+6b906702 | | `varnish-modules` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 | | `varnish-modules-debuginfo` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 | | `varnish-modules-debugsource` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 | | `varnish` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-devel` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-docs` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-modules` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish-modules-debuginfo` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish-modules-debugsource` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-devel` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-docs` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:6.0.6-2.module+el8.4.0+21799+2c737c67.5 | | `varnish-modules` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish-modules-debuginfo` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish-modules-debugsource` | Red Hat:rhel_e4s:8.4::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | | `varnish` | Red Hat:rhel_eus:8.6::appstream | All versions | 0:6.0.8-2.module+el8.6.0+21852+17475f6a.3 | | `varnish-devel` | Red Hat:rhel_eus:8.6::appstream | All versions | 0:6.0.8-2.module+el8.6.0+21852+17475f6a.3 | | `varnish-docs` | Red Hat:rhel_eus:8.6::appstream | All versions | 0:6.0.8-2.module+el8.6.0+21852+17475f6a.3 | | `varnish-modules` | Red Hat:rhel_eus:8.6::appstream | All versions | 0:0.15.0-6.module+el8.5.0+11976+0b4af72d | ## How do I fix CVE-2024-30156? Upgrade to a fixed version. ## Is CVE-2024-30156 being exploited? There is no known exploitation of CVE-2024-30156 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-30156 and fix it if it is affected. What it is: CVE-2024-30156 is a high-severity denial of service vulnerability in n/a, published on 24 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-30156 in the wild and no public exploit code. Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-30156/ (Markdown: https://insights.sbomify.com/CVE-2024-30156/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-30156 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-30156 - OSV: https://osv.dev/vulnerability/CVE-2024-30156 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-30156/ Summaries are generated and may contain mistakes; the official description above is the record.