RHSA-2021:3837HighCVSS 9.0

Red Hat Security Advisory: httpd:2.4 security update

Published
October 13, 2021
Last Modified
August 8, 2026

🔗 CVE IDs covered (1)

CVE-2021-40438 →

📋 Description

CVE-2021-40438 — httpd: mod_proxy: SSRF via a crafted request uri-path containing "unix:"

🎯 Affected products81

  • Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.src (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debugsource-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debugsource-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debugsource-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-debugsource-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-devel-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-devel-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-devel-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-devel-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-filesystem-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.noarch (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-manual-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.noarch (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.s390x (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • httpd-tools-debuginfo-0:2.4.37-16.module+el8.1.0+12900+7e6e5641.1.x86_64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • mod_http2-0:1.11.3-3.module+el8.1.0+7763+babdfe5b.1.aarch64 (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • mod_http2-0:1.11.3-3.module+el8.1.0+7763+babdfe5b.1.ppc64le (httpd:2.4) as a component of Red Hat Enterprise Linux AppStream EUS (v. 8.1)
  • +51 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing the updated packages, the httpd daemon will be restarted automatically. Workaround: Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.

🔗 References (4)