RHSA-2021:3576MediumCVSS 7.5

Red Hat Security Advisory: krb5 security update

Published
September 21, 2021
Last Modified
August 4, 2026

🔗 CVE IDs covered (2)

CVE-2021-36222 →CVE-2021-37750 →

📋 Description

CVE-2021-36222 — krb5: Sending a request containing PA-ENCRYPTED-CHALLENGE padata element without using FAST could result in NULL dereference in KDC which leads to DoS CVE-2021-37750 — krb5: NULL pointer dereference in process_tgs_req() in kdc/do_tgs_req.c via a FAST inner body that lacks server field

🎯 Affected products81

  • Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-0:1.18.2-8.3.el8_4.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debuginfo-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debuginfo-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debuginfo-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debuginfo-0:1.18.2-8.3.el8_4.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debuginfo-0:1.18.2-8.3.el8_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debugsource-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debugsource-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debugsource-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debugsource-0:1.18.2-8.3.el8_4.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-debugsource-0:1.18.2-8.3.el8_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-0:1.18.2-8.3.el8_4.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-0:1.18.2-8.3.el8_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-debuginfo-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-debuginfo-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-debuginfo-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-debuginfo-0:1.18.2-8.3.el8_4.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-devel-debuginfo-0:1.18.2-8.3.el8_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-0:1.18.2-8.3.el8_4.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-0:1.18.2-8.3.el8_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-debuginfo-0:1.18.2-8.3.el8_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-debuginfo-0:1.18.2-8.3.el8_4.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • krb5-libs-debuginfo-0:1.18.2-8.3.el8_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • +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, running Kerberos services (krb5kdc, kadmin, and kprop) will be restarted automatically.

🔗 References (5)