CVE-2020-9490 Denial of service in Apache HTTP Server
High 7.5
Published
Updated
Check this codebase for CVE-2020-9490 and fix it if it is affected.
What it is: CVE-2020-9490 is a high-severity denial of service vulnerability in Apache Http Server, published on 7 Aug 2020. 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-2020-9490 in the wild and no public exploit code.
Affected packages and fixed versions:
- apache (Bitnami): affected from 2.4.20; fixed in 2.4.46
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-2020-9490/ (Markdown: https://insights.sbomify.com/CVE-2020-9490/index.md)
A crafted Cache-Digest header in HTTP/2 requests crashes the Apache HTTP Server when pushing resources, requiring HTTP/2 push to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-9490?
CVE-2020-9490 is a high-severity denial of service vulnerability in Apache Http Server, published on 7 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.
Weakness: CWE-444
Which versions are affected by CVE-2020-9490?
1 open source package ship an affected version, including apache. It affects 25 products.
| Package | Affected | Fixed in |
|---|---|---|
apache Bitnami | From 2.4.20 | 2.4.46 |
Linux distribution packages (39)
httpd Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-devel Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-filesystem Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-manual Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-tools Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd-tools-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_http2 Red Hat:enterprise_linux:8::appstream | All versions | 0:1.11.3-3.module+el8.2.0+7758+84b4ca3e.1 |
mod_http2-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:1.11.3-3.module+el8.2.0+7758+84b4ca3e.1 |
mod_http2-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:1.11.3-3.module+el8.2.0+7758+84b4ca3e.1 |
mod_ldap Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_ldap-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_md Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-7.module+el8.2.0+5531+7e4d69a2 |
mod_md-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-7.module+el8.2.0+5531+7e4d69a2 |
mod_md-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-7.module+el8.2.0+5531+7e4d69a2 |
mod_proxy_html Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_proxy_html-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_session Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_session-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_ssl Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-21.module+el8.2.0+5008+cca404a3 |
mod_ssl-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-21.module+el8.2.0+5008+cca404a3 |
httpd Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-debugsource Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-devel Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-filesystem Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-manual Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-tools Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
httpd-tools-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_http2 Red Hat:rhel_e4s:8.0::appstream | All versions | 0:1.11.3-3.module+el8.0.0+7808+f6c0e84d.1 |
mod_http2-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:1.11.3-3.module+el8.0.0+7808+f6c0e84d.1 |
mod_http2-debugsource Red Hat:rhel_e4s:8.0::appstream | All versions | 0:1.11.3-3.module+el8.0.0+7808+f6c0e84d.1 |
mod_ldap Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_ldap-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_md Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_md-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_proxy_html Red Hat:rhel_e4s:8.0::appstream | All versions | 1:2.4.37-12.module+el8.0.0+4096+eb40e6da |
mod_proxy_html-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 1:2.4.37-12.module+el8.0.0+4096+eb40e6da |
Products include Apache Http Server, Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Opensuse Leap, Oracle Communications Element Manager and 19 more.
How do I fix CVE-2020-9490?
Upgrade apache to 2.4.46 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-9490 being exploited?
There is no known exploitation of CVE-2020-9490 in the wild and no public exploit code.
Other vulnerabilities in Apache Http Server
Sources
Also known as ALPINE-CVE-2020-9490, BIT-apache-2020-9490, CLEANSTART-2026-LV72653, DEBIAN-CVE-2020-9490, GHSA-f2jx-wr3j-25w5, RHSA-2020:3714 and 4 more.