Bug 1869473 (CVE-2020-8622)

Summary: CVE-2020-8622 bind: truncated TSIG response can lead to an assertion failure
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: aegorenk, anon.amish, apmukher, lilhuang, mruprich, msehnout, pemensik, pzhukov, security-response-team, sujagtap, thozza, vonsch, yozone, zdohnal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: bind 9.11.22, bind 9.16.6, bind 9.17.4 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in bind. An assertion failure can occur when trying to verify a truncated response to a TSIG-signed request. The highest threat from this vulnerability is to system availability.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2020-10-08 02:21:12 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: 1869474, 1869475, 1870904, 1872084, 1874951, 1874954, 1874957, 1874960    
Bug Blocks: 1869469    
Attachments:
Description Flags
Patch against 9.11.22 none

Description Huzaifa S. Sidhpurwala 2020-08-18 04:52:03 UTC 
As per upstream advisory:

Attempting to verify a truncated response to a TSIG-signed request leads to an assertion failure.

An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit.

Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit.
Comment 1 Huzaifa S. Sidhpurwala 2020-08-18 04:52:07 UTC 
Acknowledgments:

Name: ISC
Upstream: Dave Feldman (Oracle), Jeff Warren (Oracle), Joel Cunningham (Oracle)
Comment 3 Huzaifa S. Sidhpurwala 2020-08-18 06:49:51 UTC 
Created attachment 1711687 [details]
Patch against 9.11.22
Comment 4 Huzaifa S. Sidhpurwala 2020-08-21 02:18:42 UTC 
External References:

https://kb.isc.org/docs/cve-2020-8622
Comment 5 Huzaifa S. Sidhpurwala 2020-08-21 02:19:33 UTC 
Created bind tracking bugs for this issue:

Affects: fedora-all [bug 1870904]
Comment 14 Huzaifa S. Sidhpurwala 2020-08-26 15:59:23 UTC 
Upstream commit: https://gitlab.isc.org/isc-projects/bind9/-/commit/6ed167ad0a647dff20c8cb08c944a7967df2d415
Comment 33 errata-xmlrpc 2020-10-07 20:16:42 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2020:4183 https://access.redhat.com/errata/RHSA-2020:4183
Comment 34 Product Security DevOps Team 2020-10-08 02:21:12 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-2020-8622
Comment 40 errata-xmlrpc 2020-11-04 01:30:49 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4500 https://access.redhat.com/errata/RHSA-2020:4500
Comment 43 errata-xmlrpc 2020-11-10 10:01:00 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Extended Update Support

Via RHSA-2020:4992 https://access.redhat.com/errata/RHSA-2020:4992
Comment 44 errata-xmlrpc 2020-11-10 13:00:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:5011 https://access.redhat.com/errata/RHSA-2020:5011
Comment 46 errata-xmlrpc 2020-11-24 11:33:31 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Extended Update Support

Via RHSA-2020:5203 https://access.redhat.com/errata/RHSA-2020:5203