CVE-2021-40438
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.
- Score
- CVSS 3.1 9.0 Critical
- Status
- Analyzed - security@apache.org
- Published
- 2021-09-16
- Last modified
- 2026-08-06
- Known exploited (CISA KEV)
- since 2021-12-01, action due 2021-12-15: Apply updates per vendor instructions.
- Weaknesses
- CWE-918
Affected products
- Http Server (Apache)
- Apache Http Server (Apache Software Foundation)
- Brocade Fabric Operating System Firmware (Broadcom)
- Debian Linux (Debian)
- F5os (F5)
- Fedora (Fedoraproject)
- Cloud Backup (Netapp)
- Clustered Data Ontap (Netapp)
- Storagegrid (Netapp)
- Enterprise Manager Ops Center (Oracle)
- Http Server (Oracle)
- Instantis Enterprisetrack (Oracle)
- Secure Global Desktop (Oracle)
- Zfs Storage Appliance Kit (Oracle)
- Enterprise Linux (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 Update Services For Sap Solutions (Redhat)
- Enterprise Linux Workstation (Redhat)
- Jboss Core Services (Redhat)
- Software Collections (Redhat)
- Rocky Linux (Resf)
- Ruggedcom Nms (Siemens)
- Sinec Nms (Siemens)
- Sinema Remote Connect Server (Siemens)
- Sinema Server (Siemens)
- Tenable.sc (Tenable)
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.…
- https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.o…
- https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.…
- https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.…
- https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.…
- https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.…
- https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.…
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7…
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3…
- https://security.gentoo.org/glsa/202208-20
- https://security.netapp.com/advisory/ntap-20211008-0004/
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ
- https://www.debian.org/security/2021/dsa-4982
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.tenable.com/security/tns-2021-17
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40438
