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Status published
Unknown
CVE-2021-40438
mod_proxy SSRF
Vulnerability 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.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
THREAT MONITOR
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Credits & Attribution
The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:
- The issue was discovered by the Apache HTTP security team while analysing CVE-2021-36160
References
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html
- https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E
- https://www.debian.org/security/2021/dsa-4982
- https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.org%3E
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.tenable.com/security/tns-2021-17
- https://security.netapp.com/advisory/ntap-20211008-0004/
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf
- https://security.gentoo.org/glsa/202208-20
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Affected Vendor
Apache Software Foundation
View all reports →Affected Software
Apache HTTP Server
Vulnerable Versions:
Apache HTTP Server 2.4
Timeline
Official Publish:
September 16th, 2021
Last Modified:
October 21st, 2025
Added to House:
July 21st, 2026
CVSS Vectors
No vector data available