CVE-2021-44790 Possible buffer overflow when parsing multipart content in mod_lua of Apache HTTP Server 2.4.51 and earlier
Critical 9.8
Published
Updated
Check this codebase for CVE-2021-44790 and fix it if it is affected.
What it is: CVE-2021-44790 is a critical memory corruption vulnerability in Apache Http Server, published on 20 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-44790 exists.
Affected packages and fixed versions:
- apache (Bitnami): affected all versions; fixed in 2.4.52
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-2021-44790/ (Markdown: https://insights.sbomify.com/CVE-2021-44790/index.md)
A crafted request body can cause a buffer overflow in the mod_lua multipart parser, potentially allowing code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-44790?
CVE-2021-44790 is a critical memory corruption vulnerability in Apache Http Server, published on 20 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts). The Apache httpd team is not aware of an exploit for the vulnerabilty though it might be possible to craft one. This issue affects Apache HTTP Server 2.4.51 and earlier.
Weakness: CWE-787
Which versions are affected by CVE-2021-44790?
1 open source package ship an affected version, including apache. It affects 14 products.
| Package | Affected | Fixed in |
|---|---|---|
apache Bitnami | All versions | 2.4.52 |
Linux distribution packages (39)
httpd AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
httpd-devel AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
httpd-filesystem AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
httpd-manual AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
httpd-tools AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
mod_http2 AlmaLinux:8 | All versions | 1.15.7-3.module_el8.5.0+2609+b30d9eec |
mod_ldap AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
mod_md AlmaLinux:8 | All versions | 1:2.0.8-8.module_el8.5.0+2609+b30d9eec |
mod_md AlmaLinux:8 | All versions | 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa |
mod_proxy_html AlmaLinux:8 | All versions | 1:2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
mod_session AlmaLinux:8 | All versions | 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
mod_ssl AlmaLinux:8 | All versions | 1:2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma |
httpd Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-devel Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-filesystem Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-manual Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-tools Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd-tools-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_http2 Red Hat:enterprise_linux:8::appstream | All versions | 0:1.15.7-3.module+el8.4.0+8625+d397f3da |
mod_http2-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:1.15.7-3.module+el8.4.0+8625+d397f3da |
mod_http2-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:1.15.7-3.module+el8.4.0+8625+d397f3da |
mod_ldap Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_ldap-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_md Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-8.module+el8.3.0+6814+67d1e611 |
mod_md-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-8.module+el8.3.0+6814+67d1e611 |
mod_md-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 1:2.0.8-8.module+el8.3.0+6814+67d1e611 |
mod_proxy_html Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_proxy_html-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_session Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_session-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_ssl Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
mod_ssl-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:2.4.37-43.module+el8.5.0+13806+b30d9eec.1 |
httpd Red Hat:rhel_e4s:8.1::appstream | All versions | 0:2.4.37-16.module+el8.1.0+13809+822d170a.3 |
httpd-debuginfo Red Hat:rhel_e4s:8.1::appstream | All versions | 0:2.4.37-16.module+el8.1.0+13809+822d170a.3 |
httpd-debugsource Red Hat:rhel_e4s:8.1::appstream | All versions | 0:2.4.37-16.module+el8.1.0+13809+822d170a.3 |
httpd-devel Red Hat:rhel_e4s:8.1::appstream | All versions | 0:2.4.37-16.module+el8.1.0+13809+822d170a.3 |
httpd-filesystem Red Hat:rhel_e4s:8.1::appstream | All versions | 0:2.4.37-16.module+el8.1.0+13809+822d170a.3 |
Products include Apache Http Server, Apple Mac Os X, Apple Macos, Debian Debian Linux, Fedoraproject Fedora, Netapp Cloud Backup and 8 more.
How do I fix CVE-2021-44790?
Upgrade apache to 2.4.52 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-44790 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-44790 exists.
Public exploit code: 1 Exploit-DB entry and 3 proofs of concept on GitHub.
Other vulnerabilities in Apache Http Server
Sources
Also known as ALPINE-CVE-2021-44790, ALSA-2022:0258, AZL-7044, BIT-apache-2021-44790, CLEANSTART-2026-DN02833, CLSA-2022-1643822315 and 8 more.