Description
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
Published: 2021-09-16
Score: 9 Critical
EPSS: 94.4% High
KEV: Yes
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-2776-1 apache2 security update
Debian DSA Debian DSA DSA-4982-1 apache2 security update
Ubuntu USN Ubuntu USN USN-5090-1 Apache HTTP Server vulnerabilities
Ubuntu USN Ubuntu USN USN-5090-2 Apache HTTP Server vulnerabilities
References
Link Providers
https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf cve-icon cve-icon
https://httpd.apache.org/security/vulnerabilities_24.html cve-icon cve-icon
https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.org%3E cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2021-40438 cve-icon
https://security.gentoo.org/glsa/202208-20 cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20211008-0004/ cve-icon cve-icon
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ cve-icon cve-icon
https://www.cisa.gov/known-exploited-vulnerabilities-catalog cve-icon
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40438 cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2021-40438 cve-icon
https://www.debian.org/security/2021/dsa-4982 cve-icon cve-icon
https://www.oracle.com/security-alerts/cpuapr2022.html cve-icon cve-icon
https://www.oracle.com/security-alerts/cpujan2022.html cve-icon cve-icon
https://www.tenable.com/security/tns-2021-17 cve-icon cve-icon
History

Wed, 22 Oct 2025 00:30:00 +0000


Tue, 21 Oct 2025 20:30:00 +0000


Tue, 21 Oct 2025 19:30:00 +0000


Fri, 16 May 2025 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat enterprise Linux Eus
Redhat enterprise Linux For Arm 64
Redhat enterprise Linux For Arm 64 Eus
Redhat enterprise Linux For Ibm Z Systems
Redhat enterprise Linux For Ibm Z Systems Eus
Redhat enterprise Linux For Ibm Z Systems Eus S390x
Redhat enterprise Linux For Power Big Endian
Redhat enterprise Linux For Power Little Endian
Redhat enterprise Linux For Power Little Endian Eus
Redhat enterprise Linux For Scientific Computing
Redhat enterprise Linux Server
Redhat enterprise Linux Server Aus
Redhat enterprise Linux Server For Power Little Endian Update Services For Sap Solutions
Redhat enterprise Linux Server Tus
Redhat enterprise Linux Server Update Services For Sap Solutions
Redhat enterprise Linux Server Workstation
Redhat enterprise Linux Update Services For Sap Solutions
Redhat enterprise Linux Workstation
Redhat software Collections
Resf
Resf rocky Linux
CPEs cpe:2.3:a:redhat:jboss_core_services:1.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:software_collections:1.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_arm_64:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:7.0_s390x:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.1:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus_s390x:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_big_endian:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.1:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_scientific_computing:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_workstation:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:8.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
cpe:2.3:o:resf:rocky_linux:8.0:*:*:*:*:*:*:*
Vendors & Products Redhat enterprise Linux Eus
Redhat enterprise Linux For Arm 64
Redhat enterprise Linux For Arm 64 Eus
Redhat enterprise Linux For Ibm Z Systems
Redhat enterprise Linux For Ibm Z Systems Eus
Redhat enterprise Linux For Ibm Z Systems Eus S390x
Redhat enterprise Linux For Power Big Endian
Redhat enterprise Linux For Power Little Endian
Redhat enterprise Linux For Power Little Endian Eus
Redhat enterprise Linux For Scientific Computing
Redhat enterprise Linux Server
Redhat enterprise Linux Server Aus
Redhat enterprise Linux Server For Power Little Endian Update Services For Sap Solutions
Redhat enterprise Linux Server Tus
Redhat enterprise Linux Server Update Services For Sap Solutions
Redhat enterprise Linux Server Workstation
Redhat enterprise Linux Update Services For Sap Solutions
Redhat enterprise Linux Workstation
Redhat software Collections
Resf
Resf rocky Linux

Thu, 06 Feb 2025 21:15:00 +0000

Type Values Removed Values Added
Metrics kev

{'dateAdded': '2021-12-01'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'active', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 14 Aug 2024 00:45:00 +0000

Type Values Removed Values Added
References

Subscriptions

Apache Http Server
Broadcom Brocade Fabric Operating System Firmware
Debian Debian Linux
F5 F5os
Fedoraproject Fedora
Netapp Cloud Backup Clustered Data Ontap Storagegrid
Oracle Enterprise Manager Ops Center Http Server Instantis Enterprisetrack Secure Global Desktop Zfs Storage Appliance Kit
Redhat Enterprise Linux Enterprise Linux Eus Enterprise Linux For Arm 64 Enterprise Linux For Arm 64 Eus Enterprise Linux For Ibm Z Systems Enterprise Linux For Ibm Z Systems Eus Enterprise Linux For Ibm Z Systems Eus S390x Enterprise Linux For Power Big Endian Enterprise Linux For Power Little Endian Enterprise Linux For Power Little Endian Eus Enterprise Linux For Scientific Computing Enterprise Linux Server Enterprise Linux Server Aus Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions Enterprise Linux Server Tus Enterprise Linux Server Update Services For Sap Solutions Enterprise Linux Server Workstation Enterprise Linux Update Services For Sap Solutions Enterprise Linux Workstation Jboss Core Services Rhel Aus Rhel E4s Rhel Eus Rhel Software Collections Rhel Tus Software Collections
Resf Rocky Linux
Siemens Ruggedcom Nms Sinec Nms Sinema Remote Connect Server Sinema Server
Tenable Tenable.sc
cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2025-10-21T23:25:32.274Z

Reserved: 2021-09-02T00:00:00.000Z

Link: CVE-2021-40438

cve-icon Vulnrichment

Updated: 2024-08-04T02:44:10.131Z

cve-icon NVD

Status : Analyzed

Published: 2021-09-16T15:15:07.633

Modified: 2025-10-27T17:37:06.747

Link: CVE-2021-40438

cve-icon Redhat

Severity : Important

Publid Date: 2021-09-16T00:00:00Z

Links: CVE-2021-40438 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses