Bug 1901041 (CVE-2020-28196) - CVE-2020-28196 krb5: unbounded recursion via an ASN.1-encoded Kerberos message in lib/krb5/asn.1/asn1_encode.c may lead to DoS
Summary: CVE-2020-28196 krb5: unbounded recursion via an ASN.1-encoded Kerberos messag...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-28196
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1902657 1906492
Blocks: 1901042
TreeView+ depends on / blocked
 
Reported: 2020-11-24 10:55 UTC by Marian Rehak
Modified: 2021-06-16 15:49 UTC (History)
24 users (show)

Fixed In Version: krb5 1.17.2, krb5 1.18.3
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in krb5. MIT Kerberos 5 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.
Clone Of:
Environment:
Last Closed: 2021-05-18 14:36:14 UTC
Embargoed:

Attachments (Terms of Use)

Description Marian Rehak 2020-11-24 10:55:14 UTC 
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.

Upstream Reference:

https://krbdev.mit.edu/rt/Ticket/Display.html?id=8959
Comment 1 Stefan Cornelius 2020-11-24 12:30:54 UTC 
Patch:
https://github.com/krb5/krb5/commit/57415dda6cf04e73ffc3723be518eddfae599bfd
Comment 5 Sandro Bonazzola 2020-12-02 08:47:55 UTC 
Any plan to get this fixed in RHEL 8? I see 1.18.2 shipped in RHEL 8.3 so it should be affected right?
Comment 12 errata-xmlrpc 2021-05-18 13:32:17 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1593 https://access.redhat.com/errata/RHSA-2021:1593
Comment 13 Product Security DevOps Team 2021-05-18 14:36:14 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-28196
Comment 14 errata-xmlrpc 2021-06-03 10:24:21 UTC 
This issue has been addressed in the following products:

  Red Hat Virtualization 4 for Red Hat Enterprise Linux 8

Via RHSA-2021:2239 https://access.redhat.com/errata/RHSA-2021:2239
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