CVE-2021-40438

Known Exploited
mod_proxy SSRF

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.

Category

9.0
CVSS
Severity: Critical
CVSS 3.1 •
CVSS 2.0 •
EPSS 94.43% Top 5%
KEV Since 
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory debian.org Vendor Advisory cisco.com Vendor Advisory gentoo.org Vendor Advisory apache.org
Affected: Apache Software Foundation Apache HTTP Server
Published at:
Updated at:

References

Link Tags
https://httpd.apache.org/security/vulnerabilities_24.html release notes vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/ release notes vendor advisory
https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/ release notes vendor advisory
https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html third party advisory mailing list
https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E mailing list
https://www.debian.org/security/2021/dsa-4982 vendor advisory mailing list third party advisory
https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.org%3E mailing list
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ vendor advisory broken link third party advisory
https://www.oracle.com/security-alerts/cpujan2022.html third party advisory patch
https://www.tenable.com/security/tns-2021-17 third party advisory
https://security.netapp.com/advisory/ntap-20211008-0004/ third party advisory
https://www.oracle.com/security-alerts/cpuapr2022.html third party advisory patch
https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf third party advisory
https://security.gentoo.org/glsa/202208-20 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-40438?
CVE-2021-40438 has been scored as a critical severity vulnerability.
How to fix CVE-2021-40438?
To fix CVE-2021-40438, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-40438 being actively exploited in the wild?
It is confirmed that CVE-2021-40438 is actively exploited. Be extra cautious if you are using vulnerable components. According to its EPSS score, there is a ~94% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-40438?
CVE-2021-40438 affects Apache Software Foundation Apache HTTP Server.
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