Vulnerability/
RHSA-2021:3837

RHSA-2021:3837: Important: httpd:2.4 security update

Published Oct 13, 2021

·

Updated

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.<br>Security Fix(es):<br><li> httpd: modproxy: SSRF via a crafted request uri-path containing "unix:" (CVE-2021-40438)</li> For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Affected Software

26 affected componentsFixes available

redhat/httpd<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-filesystem<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-manual<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debugsource<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-devel<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debugsource<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-devel<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-debugsource<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-devel<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd-tools-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1

2.4.37-16.module+el8.1.0+12900+7e6e5641.1

redhat/httpd<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

redhat/httpd-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

redhat/httpd-debugsource<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

redhat/httpd-devel<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

redhat/httpd-tools<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

redhat/httpd-tools-debuginfo<2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aa

Remediation

Event History

May 29, 2026

Advisory Published

via Red Hat·05:20 PM

Data Sourced

via Red Hat·05:20 PM

RemedyDescriptionAffected Software

Frequently Asked Questions

1

What is the severity of RHSA-2021:3837?

The severity of RHSA-2021:3837 is rated as important due to the SSRF vulnerability found in mod_proxy.

2

How do I fix RHSA-2021:3837?

To fix RHSA-2021:3837, update the httpd package to version 2.4.37-16.module+el8.1.0+12900+7e6e5641.1 or later.

3

What vulnerabilities are addressed in RHSA-2021:3837?

RHSA-2021:3837 addresses a SSRF vulnerability described as CVE-2021-40438 in the Apache mod_proxy module.

4

Which versions of httpd are affected by RHSA-2021:3837?

RHSA-2021:3837 affects httpd versions prior to 2.4.37-16.module+el8.1.0+12900+7e6e5641.1.

5

Is there any workaround for RHSA-2021:3837?

The best course of action for RHSA-2021:3837 is to apply the available patches and updates as there are no official workarounds provided.

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