Bug 1852009 (CVE-2020-14308)

Summary: CVE-2020-14308 grub2: grub_malloc does not validate allocation size allowing for arithmetic overflow and subsequent heap-based buffer overflow
Product: [Other] Security Response Reporter: Marco Benatto <mbenatto>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bootloader-eng-team, fmartine, lkundrak, pjones, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: grub 2.06 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in current grub2 versions as shipped with Red Hat Enterprise Linux 7 and 8, where the grub memory allocator doesn't check for possible arithmetic overflows on the requested allocation size. This issue leads the function to return invalid memory allocations, causing heap-based overflows in several code paths. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-07-29 19:27:46 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: 1853688, 1853689, 1853690, 1853691, 1853692, 1853693, 1853694, 1853695, 1853696, 1853697, 1853698, 1853699, 1863017    
Bug Blocks: 1852004    

Description Marco Benatto 2020-06-29 15:23:25 UTC
Currently grub_malloc() function and related memory infrastructure underlying it doesn't fully validate the allocation size. This can lead
to arithmetic overflows leading to invalid memory allocations, which can be leverage to heap-based overflows in several code paths.

Comment 4 Marco Benatto 2020-07-03 15:04:30 UTC
In the current grub versions, grub_malloc() malloc function doesn't validate if the allocation size may overflow the maximum type representation. This leads grub_malloc() to return invalid allocations, an attacker may leverage causing memory corruption leading to possible integrity, confidentiality and availability impacts. To be able to exploit this the attacker needs local privileged or physical access to the machine.

Comment 5 Marco Benatto 2020-07-07 13:41:24 UTC
Acknowledgments:

Name: Chris Coulson (Ubuntu Security Team)

Comment 8 errata-xmlrpc 2020-07-29 18:30:35 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3216 https://access.redhat.com/errata/RHSA-2020:3216

Comment 9 Product Security DevOps Team 2020-07-29 19:27:46 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-2020-14308

Comment 10 errata-xmlrpc 2020-07-29 19:34:00 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:3217 https://access.redhat.com/errata/RHSA-2020:3217

Comment 11 errata-xmlrpc 2020-07-29 19:37:44 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Extended Update Support

Via RHSA-2020:3223 https://access.redhat.com/errata/RHSA-2020:3223

Comment 12 errata-xmlrpc 2020-07-29 20:14:42 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.0 Update Services for SAP Solutions

Via RHSA-2020:3227 https://access.redhat.com/errata/RHSA-2020:3227

Comment 13 errata-xmlrpc 2020-08-03 10:57:00 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.2 Advanced Update Support

Via RHSA-2020:3273 https://access.redhat.com/errata/RHSA-2020:3273

Comment 14 errata-xmlrpc 2020-08-03 11:13:56 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-2020:3275 https://access.redhat.com/errata/RHSA-2020:3275

Comment 15 errata-xmlrpc 2020-08-03 11:52:22 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Extended Update Support

Via RHSA-2020:3271 https://access.redhat.com/errata/RHSA-2020:3271

Comment 16 errata-xmlrpc 2020-08-03 12:02:15 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.3 Advanced Update Support
  Red Hat Enterprise Linux 7.3 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.3 Telco Extended Update Support

Via RHSA-2020:3276 https://access.redhat.com/errata/RHSA-2020:3276

Comment 17 errata-xmlrpc 2020-08-03 12:05:47 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Extended Update Support

Via RHSA-2020:3274 https://access.redhat.com/errata/RHSA-2020:3274

Comment 18 Marco Benatto 2020-08-03 13:45:23 UTC
Created grub2 tracking bugs for this issue:

Affects: fedora-all [bug 1863017]