CVE-2021-33193

high
New! CVE Severity Now Using CVSS v3

The calculated severity for CVEs has been updated to use CVSS v3 by default. CVEs that do not have a CVSS v3 score will fall back CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Description

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

https://portswigger.net/research/http2

https://github.com/apache/httpd/commit/ecebcc035ccd8d0e2984fe41420d9e944f456b3c.patch

https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E

https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E

https://security.netapp.com/advisory/ntap-20210917-0004/

https://lists.fedoraproject.org/archives/list/[email protected]/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/

https://www.tenable.com/security/tns-2021-17

https://lists.fedoraproject.org/archives/list/[email protected]/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ

Details

Source: MITRE

Published: 2021-08-16

Updated: 2021-11-28

Risk Information

CVSS v2

Base Score: 5

Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N

Impact Score: 2.9

Exploitability Score: 10

Severity: MEDIUM

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Impact Score: 3.6

Exploitability Score: 3.9

Severity: HIGH

Vulnerable Software

Configuration 1

OR

cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* versions from 2.4.17 to 2.4.48 (inclusive)

Configuration 2

OR

cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

Configuration 3

OR

cpe:2.3:a:tenable:tenable.sc:*:*:*:*:*:*:*:* versions up to 5.19.1 (inclusive)

Tenable Plugins

View all (16 total)

IDNameProductFamilySeverity
154240Tenable SecurityCenter 5.16.0 < 5.19.2 Multiple Vulnerabilities (TNS-2021-17)NessusMisc.
critical
154188Amazon Linux AMI : httpd24 (ALAS-2021-1543)NessusAmazon Linux Local Security Checks
critical
154179Amazon Linux 2 : httpd (ALAS-2021-1716)NessusAmazon Linux Local Security Checks
critical
154067SUSE SLES15 Security Update : apache2 (SUSE-SU-2021:3335-1)NessusSuSE Local Security Checks
critical
153939Photon OS 3.0: Httpd PHSA-2021-3.0-0305NessusPhotonOS Local Security Checks
high
153816FreeBSD : Apache httpd -- multiple vulnerabilities (882a38f9-17dd-11ec-b335-d4c9ef517024)NessusFreeBSD Local Security Checks
critical
153768Ubuntu 18.04 LTS / 20.04 LTS / 21.04 : Apache HTTP Server vulnerabilities (USN-5090-1)NessusUbuntu Local Security Checks
critical
153743Photon OS 2.0: Httpd PHSA-2021-2.0-0393NessusPhotonOS Local Security Checks
high
153689Photon OS 1.0: Httpd PHSA-2021-1.0-0435NessusPhotonOS Local Security Checks
high
153585Apache >= 2.4.17 < 2.4.49 mod_http2NessusWeb Servers
high
153456Slackware Linux 14.0 / 14.1 / 14.2 / current httpd Multiple Vulnerabilities (SSA:2021-259-01)NessusSlackware Local Security Checks
critical
112981Apache 2.4.x < 2.4.49 Multiple VulnerabilitiesWeb Application ScanningComponent Vulnerability
critical
153114openSUSE 15 Security Update : apache2 (openSUSE-SU-2021:1234-1)NessusSuSE Local Security Checks
high
153022SUSE SLED12 / SLES12 Security Update : apache2 (SUSE-SU-2021:2918-1)NessusSuSE Local Security Checks
high
152998openSUSE 15 Security Update : apache2 (openSUSE-SU-2021:2954-1)NessusSuSE Local Security Checks
high
152993SUSE SLED15 / SLES15 Security Update : apache2 (SUSE-SU-2021:2954-1)NessusSuSE Local Security Checks
high