Bug 1802563 (CVE-2020-8647) - CVE-2020-8647 kernel: out-of-bounds read in in vc_do_resize function in drivers/tty/vt/vt.c
Summary: CVE-2020-8647 kernel: out-of-bounds read in in vc_do_resize function in drive...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-8647
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: 1802564 1817838 1817839 1817840 1817841 1817842 1818730 1818732 1818733 1818735 2050633 2059164
Blocks: 1802567
TreeView+ depends on / blocked
 
Reported: 2020-02-13 12:04 UTC by Dhananjay Arunesh
Modified: 2023-12-15 17:19 UTC (History)
46 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2020-09-29 21:59:51 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2020:4416 0 None None None 2020-10-29 15:10:09 UTC
Red Hat Product Errata RHBA-2020:4417 0 None None None 2020-10-29 15:08:40 UTC
Red Hat Product Errata RHBA-2020:4418 0 None None None 2020-10-29 15:14:06 UTC
Red Hat Product Errata RHBA-2020:4419 0 None None None 2020-10-29 15:12:31 UTC
Red Hat Product Errata RHBA-2020:4420 0 None None None 2020-10-29 15:51:26 UTC
Red Hat Product Errata RHBA-2022:1316 0 None None None 2022-04-12 10:24:57 UTC
Red Hat Product Errata RHSA-2020:4060 0 None None None 2020-09-29 20:53:17 UTC
Red Hat Product Errata RHSA-2020:4062 0 None None None 2020-09-29 18:59:16 UTC
Red Hat Product Errata RHSA-2020:4431 0 None None None 2020-11-04 00:50:35 UTC
Red Hat Product Errata RHSA-2020:4609 0 None None None 2020-11-04 02:22:44 UTC
Red Hat Product Errata RHSA-2022:1209 0 None None None 2022-04-05 15:08:04 UTC
Red Hat Product Errata RHSA-2022:1213 0 None None None 2022-04-05 15:46:31 UTC

Description Dhananjay Arunesh 2020-02-13 12:04:10 UTC 
An out of bounds read vulnerability in the virtual console/virtual terminal resize functionality.  An attacker with a local account can use the resize functionality to possibly leak kernel internal information to the local console which may be captured for use in a further attack to increase the reliability and successfulness of the next attack.


Reference:
Kernel Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206359
Proposed patch: https://lkml.org/lkml/2020/3/1/415
Comment 1 Dhananjay Arunesh 2020-02-13 12:04:57 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1802564]
Comment 2 Justin M. Forbes 2020-03-20 15:46:34 UTC 
This issue was fixed for Fedora with the 5.5.9 stable kernel updates.
Comment 10 Wade Mealing 2020-03-30 01:41:45 UTC 
Mitigation:

The attack vector can be significantly reduced by preventing users from being able to log into the local virtual console.

See the instructions on disabling local login here: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/managing_smart_cards/pam_configuration_files , See the section on "pam_console" to deny users logging into the console.  This mechanism should work from el6 forward to current versions of Red Hat Enterprise Linux.
Comment 11 Petr Matousek 2020-04-03 04:52:00 UTC 
Statement:

This flaw is rated as having Moderate impact because the information leak is limited.
Comment 12 errata-xmlrpc 2020-09-29 18:59:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4062 https://access.redhat.com/errata/RHSA-2020:4062
Comment 13 errata-xmlrpc 2020-09-29 20:53:13 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4060 https://access.redhat.com/errata/RHSA-2020:4060
Comment 14 Product Security DevOps Team 2020-09-29 21:59:51 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-2020-8647
Comment 30 errata-xmlrpc 2020-11-04 00:50:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431
Comment 31 errata-xmlrpc 2020-11-04 02:22:41 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609
Comment 34 errata-xmlrpc 2022-04-05 15:08:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:1209 https://access.redhat.com/errata/RHSA-2022:1209
Comment 35 errata-xmlrpc 2022-04-05 15:46:28 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:1213 https://access.redhat.com/errata/RHSA-2022:1213
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