CVE-2021-40438
CRITICALCVSS 9/10Actively ExploitedEPSS 100.00%
Last modified
CVE-2021-40438 is a critical-severity vulnerability rated 9/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 100.00% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
100.0th percentile
Probability of exploitation in the next 30 days. Learn more
Exploitation Status
This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by .
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Resf | Rocky Linux | 8.0 |
| Redhat | Enterprise Linux | 8.0 |
| Redhat | Enterprise Linux Eus | 8.1 |
| Redhat | Enterprise Linux Eus | 8.2 |
| Redhat | Enterprise Linux Eus | 8.4 |
| Redhat | Enterprise Linux Eus | 8.6 |
| Redhat | Enterprise Linux Eus | 8.8 |
| Redhat | Enterprise Linux For Arm 64 | 8.0 |
| Redhat | Enterprise Linux For Arm 64 Eus | 8.6 |
| Redhat | Enterprise Linux For Arm 64 Eus | 8.8 |
| Redhat | Enterprise Linux For Ibm Z Systems | 7.0_s390x |
| Redhat | Enterprise Linux For Ibm Z Systems | 8.0 |
| Redhat | Enterprise Linux For Ibm Z Systems Eus | 8.1 |
| Redhat | Enterprise Linux For Ibm Z Systems Eus | 8.4 |
| Redhat | Enterprise Linux For Ibm Z Systems Eus | 8.8 |
| Redhat | Enterprise Linux For Ibm Z Systems Eus S390x | 8.2 |
| Redhat | Enterprise Linux For Power Big Endian | 7.0 |
| Redhat | Enterprise Linux For Power Little Endian | 7.0 |
| Redhat | Enterprise Linux For Power Little Endian | 8.0 |
| Redhat | Enterprise Linux For Power Little Endian Eus | 8.1 |
| Redhat | Enterprise Linux For Power Little Endian Eus | 8.2 |
| Redhat | Enterprise Linux For Power Little Endian Eus | 8.4 |
| Redhat | Enterprise Linux For Power Little Endian Eus | 8.6 |
| Redhat | Enterprise Linux For Power Little Endian Eus | 8.8 |
| Redhat | Enterprise Linux For Scientific Computing | 7.0 |
| Redhat | Enterprise Linux Server | 7.0 |
| Redhat | Enterprise Linux Server Aus | 7.2 |
| Redhat | Enterprise Linux Server Aus | 7.3 |
| Redhat | Enterprise Linux Server Aus | 7.4 |
| Redhat | Enterprise Linux Server Aus | 7.6 |
| Redhat | Enterprise Linux Server Aus | 7.7 |
| Redhat | Enterprise Linux Server Aus | 8.2 |
| Redhat | Enterprise Linux Server Aus | 8.4 |
| Redhat | Enterprise Linux Server Aus | 8.6 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 7.6 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 7.7 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 8.1 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 8.2 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 8.4 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 8.6 |
| Redhat | Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions | 8.8 |
| Redhat | Enterprise Linux Server Tus | 7.6 |
| Redhat | Enterprise Linux Server Tus | 7.7 |
| Redhat | Enterprise Linux Server Tus | 8.2 |
| Redhat | Enterprise Linux Server Tus | 8.4 |
| Redhat | Enterprise Linux Server Tus | 8.6 |
| Redhat | Enterprise Linux Server Tus | 8.8 |
| Redhat | Enterprise Linux Server Update Services For Sap Solutions | 7.6 |
| Redhat | Enterprise Linux Server Update Services For Sap Solutions | 7.7 |
| Redhat | Enterprise Linux Update Services For Sap Solutions | 8.1 |
Showing 50 of 83 affected configurations. See NVD for the full list.
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdfThird Party Advisory
- https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211008-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQBroken Link, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4982Mailing List, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.tenable.com/security/tns-2021-17Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdfThird Party Advisory
- https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211008-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQBroken Link, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4982Mailing List, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.tenable.com/security/tns-2021-17Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40438US Government Resource
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is 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.
How severe is CVE-2021-40438?
CVE-2021-40438 has a CVSS score of 9/10 (CRITICAL severity). The EPSS model estimates a 100.00% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.
How do I fix CVE-2021-40438?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
Are you affected by CVE-2021-40438?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST