UBUNTU-CVE-2021-33193

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Source
https://ubuntu.com/security/CVE-2021-33193
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-33193.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-33193
Upstream
Downstream
Related
Published
2021-08-16T08:15:00Z
Modified
2025-09-08T16:47:11Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.

References

Affected packages

Ubuntu:18.04:LTS / apache2

Package

Name
apache2
Purl
pkg:deb/ubuntu/apache2@2.4.29-1ubuntu4.17?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.4.29-1ubuntu4.17

Affected versions

2.*

2.4.27-2ubuntu3
2.4.29-1ubuntu1
2.4.29-1ubuntu2
2.4.29-1ubuntu3
2.4.29-1ubuntu4
2.4.29-1ubuntu4.1
2.4.29-1ubuntu4.2
2.4.29-1ubuntu4.3
2.4.29-1ubuntu4.4
2.4.29-1ubuntu4.5
2.4.29-1ubuntu4.6
2.4.29-1ubuntu4.7
2.4.29-1ubuntu4.8
2.4.29-1ubuntu4.10
2.4.29-1ubuntu4.11
2.4.29-1ubuntu4.12
2.4.29-1ubuntu4.13
2.4.29-1ubuntu4.14
2.4.29-1ubuntu4.16

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-bin"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-data"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-dev"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-ssl-dev"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-suexec-custom"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-suexec-pristine"
        },
        {
            "binary_version": "2.4.29-1ubuntu4.17",
            "binary_name": "apache2-utils"
        }
    ]
}

Ubuntu:20.04:LTS / apache2

Package

Name
apache2
Purl
pkg:deb/ubuntu/apache2@2.4.41-4ubuntu3.5?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.4.41-4ubuntu3.5

Affected versions

2.*

2.4.41-1ubuntu1
2.4.41-4ubuntu1
2.4.41-4ubuntu2
2.4.41-4ubuntu3
2.4.41-4ubuntu3.1
2.4.41-4ubuntu3.3
2.4.41-4ubuntu3.4

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-bin"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-data"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-dev"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-ssl-dev"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-suexec-custom"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-suexec-pristine"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "apache2-utils"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "libapache2-mod-md"
        },
        {
            "binary_version": "2.4.41-4ubuntu3.5",
            "binary_name": "libapache2-mod-proxy-uwsgi"
        }
    ]
}