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CVE-2021-40438

mod_proxy SSRF

Basic Information

CVE State
PUBLISHED
Reserved Date
September 02, 2021
Published Date
September 16, 2021
Last Updated
February 06, 2025
Vendor
Apache Software Foundation
Product
Apache HTTP Server
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.
Tags
apache cisa nuclei_scanner

CVSS Scores

CVSS v3.1

9.0 - CRITICAL

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v2.0

6.8

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

SSVC Information

Exploitation
active
Technical Impact
total

Exploit Status

Exploited in the Wild
Yes (2025-05-10 00:00:00 UTC) Source
Proof of Concept Available
Yes (added 2021-10-28 11:48:12 UTC) Source

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

Known Exploited Vulnerability Information

Source Added Date
CISA 2021-12-01 00:00:00 UTC

Scanner Integrations

Scanner URL Date Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-40438.yaml 2025-04-26 00:00:00 UTC

Potential Proof of Concepts

Warning: These PoCs have not been tested and could contain malware. Use at your own risk.

sergiovks/CVE-2021-40438-Apache-2.4.48-SSRF-exploit

Type: github • Created: 2023-12-12 11:56:23 UTC • Stars: 7

CVE-2021-40438 Apache <= 2.4.48 SSRF exploit

Kashkovsky/CVE-2021-40438

Type: github • Created: 2022-04-03 15:24:24 UTC • Stars: 17

Apache forward request CVE

BabyTeam1024/CVE-2021-40438

Type: github • Created: 2021-10-28 11:48:12 UTC • Stars: 2

sixpacksecurity/CVE-2021-40438

Type: github • Created: 2021-10-24 10:18:08 UTC • Stars: 12

CVE-2021-40438 exploit PoC with Docker setup.

xiaojiangxl/CVE-2021-40438

Type: github • Created: 2021-10-18 02:02:43 UTC • Stars: 4

Timeline

  • CVE ID Reserved

  • CVE Published to Public

  • Proof of Concept Exploit Available

  • Added to KEVIntel

  • Detected by Nuclei