Bug 1991685 (CVE-2021-3695)

Summary:	CVE-2021-3695 grub2: Crafted PNG grayscale images may lead to out-of-bounds write in heap
Product:	[Other] Security Response	Reporter:	Marco Benatto <mbenatto>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bootloader-eng-team, fmartine, jaredz, lkundrak, mlewando, pgnet.dev, pjanda, pjones, pkotvan, rharwood, security-response-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	grub 2.12	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in grub 2, where a crafted 16-bit grayscale PNG image may lead to an out-of-bounds write. This flaw allows an attacker to corrupt the data on the heap portion of the grub2's memory, leading to possible code execution and the circumvention of the secure boot mechanism.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-06-16 21:07:12 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:	2031889, 2031890, 2031891, 2031892, 2031893, 2031894, 2031895, 2031897, 2031899, 2031901, 2031902, 2070687, 2070688, 2089810, 2094468
Bug Blocks:	1991681

Description Marco Benatto 2021-08-09 17:19:20 UTC

A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads.

Comment 5 Todd Cullum 2022-06-07 17:01:03 UTC

Created grub2 tracking bugs for this issue:

Affects: fedora-all [bug 2094468]

Comment 6 errata-xmlrpc 2022-06-16 13:51:09 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions

Via RHSA-2022:5098 https://access.redhat.com/errata/RHSA-2022:5098

Comment 7 errata-xmlrpc 2022-06-16 14:55:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:5096 https://access.redhat.com/errata/RHSA-2022:5096

Comment 8 errata-xmlrpc 2022-06-16 15:23:37 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2022:5099 https://access.redhat.com/errata/RHSA-2022:5099

Comment 9 errata-xmlrpc 2022-06-16 15:33:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:5095 https://access.redhat.com/errata/RHSA-2022:5095

Comment 10 errata-xmlrpc 2022-06-16 15:45:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:5100 https://access.redhat.com/errata/RHSA-2022:5100

Comment 11 Product Security DevOps Team 2022-06-16 21:07:11 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-2021-3695