CVE-2021-44790
CriticalPublic exploitA carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts).
Published May 17, 2022 · Updated Sep 8, 2026 · Also known as ALPINE-CVE-2021-44790, BIT-apache-2021-44790, DEBIAN-CVE-2021-44790, UBUNTU-CVE-2021-44790
Key Facts
Patch immediately- CVE-2021-44790 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting HTTP Server (Apache), Cloud Backup (Netapp), Communications Element Manager (Oracle) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 97% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.52, HTTP Server 2.4.52, apache2 2.4.18-2ubuntu3.17+esm4.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
97%
Higher than 99.8% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-44790 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Affected Products
392 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | 12.2.1.3.0, 12.2.1.4.0, >= Apache HTTP Server 2.4 | 2.4.52 |
| Cloud BackupNetapp | See advisory | n/a |
| Communications Element ManagerOracle | See advisory | 9.0 |
| Communications Operations MonitorOracle | 4.3, 4.4, 5.0 | n/a |
| Communications Session Report ManagerOracle | See advisory | 9.0 |
Patched Releases
apache
2.4.52
HTTP Server
2.4.52
apache2
2.4.18-2ubuntu3.17+esm4, 2.4.23-29.83.1, 2.4.25-3+deb9u12, 2.4.29-1ubuntu4.21, 2.4.33-3.61.1, 2.4.38-3+deb10u7, 2.4.41-4ubuntu3.9, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.52-1, 2.4.52-1.1, 2.4.52-1~deb11u2, 2.4.52-1ubuntu1, 2.4.52-r0, 2.4.66-150400.6.57.1, 2.4.7-1ubuntu4.22+esm3
apache2-devel
2.4.33-3.61.1, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.66-150400.6.57.1
apache2-doc
2.4.23-29.83.1, 2.4.33-3.61.1, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.66-150400.6.57.1
apache2-event
2.4.51-3.37.1
apache2-example-pages
2.4.23-29.83.1, 2.4.51-3.37.1, 2.4.51-35.7.1
apache2-prefork
2.4.23-29.83.1, 2.4.33-3.61.1, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.66-150400.6.57.1
apache2-utils
2.4.23-29.83.1, 2.4.33-3.61.1, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.66-150400.6.57.1
apache2-worker
2.4.23-29.83.1, 2.4.33-3.61.1, 2.4.51-3.37.1, 2.4.51-35.7.1, 2.4.66-150400.6.57.1
Macos
10.15.7
chromedriver
99.0.4844.84-bp153.2.75.1
chromium
99.0.4844.84-bp153.2.75.1
httpd
0:2.4.6-45.el7_3.8, 2.4.37-39.module+el8.4.0+571+fd70afb1, 2.4.37-43.0.1.module+el8.5.0+20475+4f6a8fd5.1, 2.4.37-43.module_el8.5.0+2609+b30d9eec.1.alma, 2.4.52-1, 2.4.52-1.amzn2, 2.4.52-1.amzn2022.0.1, 2.4.52-1.ph1, 2.4.52-1.ph2, 2.4.52-1.ph3, 2.4.52-1.ph4, 2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4, 2.4.6-97.0.5.el7_9.4
httpd-core
2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4
httpd-devel
2.4.37-43.0.1.module+el8.5.0+20475+4f6a8fd5.1, 2.4.52-1.amzn2, 2.4.52-1.amzn2022.0.1, 2.4.52-1.ph4, 2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4, 2.4.6-97.0.5.el7_9.4
httpd-docs
2.4.52-1.ph4
httpd-filesystem
2.4.37-43.0.1.module+el8.5.0+20475+4f6a8fd5.1, 2.4.52-1.amzn2, 2.4.52-1.amzn2022.0.1, 2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4
httpd-manual
2.4.37-43.0.1.module+el8.5.0+20475+4f6a8fd5.1, 2.4.52-1.amzn2, 2.4.52-1.amzn2022.0.1, 2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4, 2.4.6-97.0.5.el7_9.4
httpd-tools
2.4.37-43.0.1.module+el8.5.0+20475+4f6a8fd5.1, 2.4.52-1.amzn2, 2.4.52-1.amzn2022.0.1, 2.4.52-1.ph4, 2.4.54-3.amzn2022.0.3, 2.4.54-3.amzn2023.0.4, 2.4.6-97.0.5.el7_9.4
httpd:2.4
8050020220111011611.c5368500
httpd24
2.4.52-1.95.amzn1
httpd24-devel
2.4.52-1.95.amzn1
httpd24-httpd
0:2.4.34-23.el7.1
httpd24-manual
2.4.52-1.95.amzn1
Timeline
Publicly disclosed
May 17, 2022
Last updated
Sep 8, 2026
Weakness Type
- CWE-787 Out-of-bounds Write
References
- advisoryhttp://access.redhat.com/errata/RHSA-2022:0158
- advisoryhttp://access.redhat.com/errata/RHSA-2022:0162
- advisoryhttp://access.redhat.com/errata/RHSA-2022:0258
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-2332
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44228
FAQ
Common Questions.
A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts).
Affected: HTTP Server (Apache) versions 12.2.1.3.0, 12.2.1.4.0, >= Apache HTTP Server 2.4; Cloud Backup (Netapp); Communications Element Manager (Oracle), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including apache 2.4.52, HTTP Server 2.4.52, apache2 2.4.18-2ubuntu3.17+esm4.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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