CVE-2021-36740 Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request.
Medium 6.5
Published
Updated
Check this codebase for CVE-2021-36740 and fix it if it is affected.
What it is: CVE-2021-36740 is a medium-severity vulnerability in Debian Debian Linux, published on 14 Jul 2021.
Exploitation: There is no known exploitation of CVE-2021-36740 in the wild and no public exploit code.
Affected packages and fixed versions:
- varnish (Bitnami): affected from 5.0.0; fixed in 5.2.2, 6.6.1
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-2021-36740/ (Markdown: https://insights.sbomify.com/CVE-2021-36740/index.md)
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2021-36740?
CVE-2021-36740 is a medium-severity vulnerability in Debian Debian Linux, published on 14 Jul 2021.
Official description
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8.
Weakness: CWE-444
Which versions are affected by CVE-2021-36740?
1 open source package ship an affected version, including varnish. It affects 5 products.
| Package | Affected | Fixed in |
|---|---|---|
varnish Bitnami | From 5.0.0 | 5.2.2, 6.6.1 |
Linux distribution packages (26)
varnish Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.6-2.module+el8.4.0+11921+1a6539fc.1 |
varnish-devel Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.6-2.module+el8.4.0+11921+1a6539fc.1 |
varnish-docs Red Hat:enterprise_linux:8::appstream | All versions | 0:6.0.6-2.module+el8.4.0+11921+1a6539fc.1 |
varnish-modules Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc |
varnish-modules-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc |
varnish-modules-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc |
varnish Red Hat:rhel_eus:8.1::appstream | All versions | 0:6.0.2-2.module+el8.1.0+11974+ea5ba4f1 |
varnish-devel Red Hat:rhel_eus:8.1::appstream | All versions | 0:6.0.2-2.module+el8.1.0+11974+ea5ba4f1 |
varnish-docs Red Hat:rhel_eus:8.1::appstream | All versions | 0:6.0.2-2.module+el8.1.0+11974+ea5ba4f1 |
varnish-modules Red Hat:rhel_eus:8.1::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
varnish-modules-debuginfo Red Hat:rhel_eus:8.1::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
varnish-modules-debugsource Red Hat:rhel_eus:8.1::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
varnish Red Hat:rhel_eus:8.2::appstream | All versions | 0:6.0.2-2.module+el8.2.0+11973+a748eca7 |
varnish-devel Red Hat:rhel_eus:8.2::appstream | All versions | 0:6.0.2-2.module+el8.2.0+11973+a748eca7 |
varnish-docs Red Hat:rhel_eus:8.2::appstream | All versions | 0:6.0.2-2.module+el8.2.0+11973+a748eca7 |
varnish-modules Red Hat:rhel_eus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
varnish-modules-debuginfo Red Hat:rhel_eus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
varnish-modules-debugsource Red Hat:rhel_eus:8.2::appstream | All versions | 0:0.15.0-4.module+el8+2481+4078e9d2 |
rh-varnish6-varnish Red Hat:rhel_software_collections:3::el7 | All versions | 0:6.0.8-2.el7 |
rh-varnish6-varnish-devel Red Hat:rhel_software_collections:3::el7 | All versions | 0:6.0.8-2.el7 |
rh-varnish6-varnish-docs Red Hat:rhel_software_collections:3::el7 | All versions | 0:6.0.8-2.el7 |
rh-varnish6-varnish-libs Red Hat:rhel_software_collections:3::el7 | All versions | 0:6.0.8-2.el7 |
rh-varnish6-varnish-modules Red Hat:rhel_software_collections:3::el7 | All versions | 0:0.15.0-7.el7 |
rh-varnish6-varnish-modules-debuginfo Red Hat:rhel_software_collections:3::el7 | All versions | 0:0.15.0-7.el7 |
varnish Rocky Linux:8 | All versions | 0:6.0.6-2.module+el8.3.0+179+20b582cc |
varnish-modules Rocky Linux:8 | All versions | 0:0.15.0-5.module+el8.3.0+179+20b582cc |
Products include Debian Debian Linux, Fedoraproject Fedora, Varnish-Cache Varnish Cache, Varnish-Software Varnish Cache, Varnish Cache Project Varnish Cache.
How do I fix CVE-2021-36740?
Upgrade varnish to a fixed version for your release line: 5.2.2 or 6.6.1.
Is CVE-2021-36740 being exploited?
There is no known exploitation of CVE-2021-36740 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2021-36740, BIT-varnish-2021-36740, DEBIAN-CVE-2021-36740, GHSA-8vxj-gx32-j925, MGASA-2021-0387, OESA-2021-1374 and 4 more.