CVE-2021-33193

CWE-476 — NULL Pointer DereferenceCWE-120 — Classic Buffer OverflowCWE-125 — Out-of-bounds ReadCWE-918 — Server-Side Request Forgery (SSRF)11 documents9 sources
Severity
7.5HIGH
EPSS
0.7%
top 27.11%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
7
Apache Http ServerOracle Secure BackupTenable Tenable.sc+4 more
Timeline
PublishedAug 16
Latest updateMay 24

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NExploitability: 3.9 | Impact: 3.6

Affected Packages7 packages

▶NVDapache/http_server2.4.17 — 2.4.49
▶CVEListV5apache_software_foundation/apache_http_serverApache HTTP Server 2.4 2.4.17 to 2.4.48
▶Debianapache2< 2.4.48-3.1+deb11u1+3
▶Ubuntuapache2< 2.4.29-1ubuntu4.18+3
▶NVDoracle/secure_backup< 18.1.0.1.0

Also affects: Debian Linux 10.0, Fedora 34, 35

Patches

Patch: github.com ↗Patch: lists.apache.org ↗Patch: lists.apache.org ↗

🔴Vulnerability Details

5
GHSA
GHSA-p9fg-6rr5-38xc: 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↗2022-05-24
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OSV
apache2 regression↗2021-09-28
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OSV
apache2 vulnerabilities↗2021-09-27
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CVEList
Request splitting via HTTP/2 method injection and mod_proxy↗2021-08-16
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OSV
CVE-2021-33193: 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↗2021-08-16
▶

📋Vendor Advisories

5
Cisco
Multiple Vulnerabilities in Apache HTTP Server Affecting Cisco Products: November 2021↗2021-11-24
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Ubuntu
Apache HTTP Server vulnerabilities↗2021-09-27
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Microsoft
Request splitting via HTTP/2 method injection and mod_proxy↗2021-08-10
▶
Red Hat
httpd: Request splitting via HTTP/2 method injection and mod_proxy↗2021-08-05
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Debian
CVE-2021-33193: apache2 - A crafted method sent through HTTP/2 will bypass validation and be forwarded by ...↗2021
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