Bug 1953857 (CVE-2021-25215)

Summary: CVE-2021-25215 bind: An assertion check can fail while answering queries for DNAME records that require the DNAME to be processed to resolve itself
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: aegorenk, anon.amish, dns-sig, mruprich, msehnout, pemensik, pzhukov, security-response-team, vonsch, zdohnal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: bind 9.11.30, bind 9.16.14, bind 9.17.12 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in bind. The way DNAME records are processed may trigger the same RRset to the ANSWER section to be added more than once which causes an assertion check to fail. The highest threat from this flaw is to system availability.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2021-04-29 22:46:38 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1953858, 1953859, 1953860, 1953861, 1953862, 1953863, 1953864, 1953865, 1953866, 1953867, 1953868, 1953869, 1953870, 1954526, 1954903    
Bug Blocks: 1953850    
Attachments:
Description Flags
Patch against 9.11 none

Description Huzaifa S. Sidhpurwala 2021-04-27 06:05:19 UTC 
As per upstream report:

DNAME records, described in RFC 6672, provide a way to redirect a subtree of the domain name tree in the DNS. A flaw in the way named processes these records may trigger an attempt to add the same RRset to the ANSWER section more than once. This causes an assertion check in BIND to fail.

DNAME records are processed by both authoritative and recursive servers. For authoritative servers, the DNAME record triggering the flaw can be retrieved from a zone database. For servers performing recursion, such a record is processed in the course of a query sent to an authoritative server.
Comment 1 Huzaifa S. Sidhpurwala 2021-04-27 06:05:23 UTC 
Acknowledgments:

Name: ISC
Upstream: Siva Kakarla
Comment 3 Huzaifa S. Sidhpurwala 2021-04-27 06:20:48 UTC 
Created attachment 1775848 [details]
Patch against 9.11
Comment 5 Huzaifa S. Sidhpurwala 2021-04-29 03:27:39 UTC 
External References:

https://kb.isc.org/docs/cve-2021-25215
Comment 6 Huzaifa S. Sidhpurwala 2021-04-29 03:28:33 UTC 
Created bind tracking bugs for this issue:

Affects: fedora-all [bug 1954903]
Comment 7 Huzaifa S. Sidhpurwala 2021-04-29 06:13:01 UTC 
Mitigation:

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Comment 8 errata-xmlrpc 2021-04-29 11:38:36 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support

Via RHSA-2021:1468 https://access.redhat.com/errata/RHSA-2021:1468
Comment 9 errata-xmlrpc 2021-04-29 14:30:54 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:1469 https://access.redhat.com/errata/RHSA-2021:1469
Comment 10 Product Security DevOps Team 2021-04-29 22:46:38 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-2021-25215
Comment 12 errata-xmlrpc 2021-05-03 06:13:20 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.2 Advanced Update Support

Via RHSA-2021:1476 https://access.redhat.com/errata/RHSA-2021:1476
Comment 13 errata-xmlrpc 2021-05-03 06:17:08 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.3 Advanced Update Support

Via RHSA-2021:1475 https://access.redhat.com/errata/RHSA-2021:1475
Comment 14 errata-xmlrpc 2021-05-03 07:05:14 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.4 Advanced Update Support
  Red Hat Enterprise Linux 7.4 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.4 Telco Extended Update Support

Via RHSA-2021:1479 https://access.redhat.com/errata/RHSA-2021:1479
Comment 15 errata-xmlrpc 2021-05-03 07:39:27 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Extended Update Support

Via RHSA-2021:1477 https://access.redhat.com/errata/RHSA-2021:1477
Comment 16 errata-xmlrpc 2021-05-03 07:57:58 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Extended Update Support

Via RHSA-2021:1478 https://access.redhat.com/errata/RHSA-2021:1478
Comment 17 errata-xmlrpc 2021-05-18 18:56:37 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1989 https://access.redhat.com/errata/RHSA-2021:1989
Comment 18 errata-xmlrpc 2021-05-19 08:48:21 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Extended Update Support

Via RHSA-2021:2028 https://access.redhat.com/errata/RHSA-2021:2028
Comment 19 errata-xmlrpc 2021-05-19 09:56:40 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2021:2024 https://access.redhat.com/errata/RHSA-2021:2024