---
id: CVE-2020-28196
title: >-
  MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows
  unbounded recursion via an ASN.1-encoded Kerberos message because the
  lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths lacks a
  recursion limit.
summary: >-
  MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows
  unbounded recursion via an ASN.1-encoded Kerberos message because the
  lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths lacks a
  recursion limit.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-674
  - CWE-674
vendor: mit
product: kerberos_5
affected:
  - kerberos_5 < 1.17.2
  - 'kerberos_5 >= 1.18.0, < 1.18.3'
  - fedora = 31
  - active_iq_unified_manager
  - cloud_backup
  - oncommand_insight
  - oncommand_workflow_automation
  - snapcenter
  - communications_cloud_native_core_policy = 1.14.0
  - communications_offline_mediation_controller = 12.0.0.3.0
  - communications_pricing_design_center = 12.0.0.3.0
  - mysql_server <= 8.0.23
patched:
  - kerberos_5 1.18.3
published: '2020-11-06'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:34.147'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-28196'
references:
  - url: >-
      https://github.com/krb5/krb5/commit/57415dda6cf04e73ffc3723be518eddfae599bfd
    label: cve@mitre.org
  - url: >-
      https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    label: cve@mitre.org
  - url: >-
      https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2020/11/msg00011.html'
    label: cve@mitre.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/45KKOZQWIIIW5C45PJVGQ32AXBSYNBE7/
    label: cve@mitre.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/73IGOG6CZAVMVNS4GGRMOLOZ7B6QVA7F/
    label: cve@mitre.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPH2V3WSQTELROZK3GFCPQDOFLKIZ6H5/
    label: cve@mitre.org
  - url: 'https://security.gentoo.org/glsa/202011-17'
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20201202-0001/'
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20210513-0002/'
    label: cve@mitre.org
  - url: 'https://www.debian.org/security/2020/dsa-4795'
    label: cve@mitre.org
  - url: 'https://www.oracle.com//security-alerts/cpujul2021.html'
    label: cve@mitre.org
  - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html'
    label: cve@mitre.org
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: cve@mitre.org
  - url: >-
      https://github.com/krb5/krb5/commit/57415dda6cf04e73ffc3723be518eddfae599bfd
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2020/11/msg00011.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/45KKOZQWIIIW5C45PJVGQ32AXBSYNBE7/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/73IGOG6CZAVMVNS4GGRMOLOZ7B6QVA7F/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPH2V3WSQTELROZK3GFCPQDOFLKIZ6H5/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202011-17'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20201202-0001/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210513-0002/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2020/dsa-4795'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com//security-alerts/cpujul2021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.04417
epssPercentile: 0.91147
ingestedAt: '2026-10-14T10:25:41.180Z'
---

## Overview

MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows unbounded recursion via an ASN.1-encoded Kerberos message because the lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths lacks a recursion limit.

## Affected

- `kerberos_5 < 1.17.2`
- `kerberos_5 >= 1.18.0, < 1.18.3`
- `fedora = 31`
- `active_iq_unified_manager`
- `cloud_backup`
- `oncommand_insight`
- `oncommand_workflow_automation`
- `snapcenter`
- `communications_cloud_native_core_policy = 1.14.0`
- `communications_offline_mediation_controller = 12.0.0.3.0`
- `communications_pricing_design_center = 12.0.0.3.0`
- `mysql_server <= 8.0.23`

## Remediation

Upgrade past the affected range:

- `kerberos_5 1.18.3`