Bug 2241796 (CVE-2023-40546)

Summary: CVE-2023-40546 shim: Out-of-bounds read printing error messages
Product: [Other] Security Response Reporter: Marco Benatto <mbenatto>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: mlewando, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: shim 15.8 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in Shim when an error happened while creating a new ESL variable. If Shim fails to create the new variable, it tries to print an error message to the user; however, the number of parameters used by the logging function doesn't match the format string used by it, leading to a crash under certain circumstances.
Story Points: ---
Clone Of: Environment:
Last Closed: 2024-04-18 07:24:27 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: 2259922    
Bug Blocks: 2234588    

Description Marco Benatto 2023-10-02 18:09:25 UTC
A NULL pointer dereference error exists in mirror_one_esl() at mok.c. If shim fails to create a new ESL variable it tries to log an error message,
however one of the variables used in the LogError() function doesn't match the format string and additionally it may be NULL. A successful attack
may lead shim to crash resulting in a Denial-of-Service.

Comment 2 Marco Benatto 2024-01-23 20:29:28 UTC
Created shim tracking bugs for this issue:

Affects: fedora-all [bug 2259922]

Comment 3 Marta Lewandowska 2024-04-16 07:42:05 UTC
shim 15.8-1.el7 passed sanity testing: signatures on efi binaries are correct, booting VM, netboot / httpboot over ipv4 and ipv6 all pass

Comment 4 Marta Lewandowska 2024-04-16 07:54:27 UTC
Important update information:
The new shim revokes ALL PREVIOUS VERSIONS of GRUB2. Therefore GRUB2 MUST be updated to the latest version: grub2-2.02-0.87.el7_9.14 (RHSA-2024:128440-02) BEFORE OR SIMULTANEOUSLY with this shim in order for Secure Boot to continue to work. Failure to update GRUB2 will result in an UNBOOTABLE system.

Comment 5 errata-xmlrpc 2024-04-16 13:33:30 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Advanced Update Support
  Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.2 Telecommunications Update Service

Via RHSA-2024:1834 https://access.redhat.com/errata/RHSA-2024:1834

Comment 6 errata-xmlrpc 2024-04-16 13:41:42 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Extended Update Support

Via RHSA-2024:1835 https://access.redhat.com/errata/RHSA-2024:1835

Comment 7 Marta Lewandowska 2024-04-17 10:10:56 UTC
https://bugzilla.redhat.com/show_bug.cgi?id=2234589#c17

Comment 8 errata-xmlrpc 2024-04-18 01:37:20 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.4 Telecommunications Update Service

Via RHSA-2024:1873 https://access.redhat.com/errata/RHSA-2024:1873

Comment 9 errata-xmlrpc 2024-04-18 01:42:57 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Extended Update Support

Via RHSA-2024:1876 https://access.redhat.com/errata/RHSA-2024:1876

Comment 10 errata-xmlrpc 2024-04-18 01:51:06 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Extended Update Support

Via RHSA-2024:1883 https://access.redhat.com/errata/RHSA-2024:1883

Comment 11 errata-xmlrpc 2024-04-18 07:54:49 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2024:1903 https://access.redhat.com/errata/RHSA-2024:1903

Comment 12 errata-xmlrpc 2024-04-18 07:57:26 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2024:1902 https://access.redhat.com/errata/RHSA-2024:1902

Comment 16 errata-xmlrpc 2024-04-23 00:47:12 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2024:1959 https://access.redhat.com/errata/RHSA-2024:1959

Comment 17 errata-xmlrpc 2024-04-29 02:16:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Extended Update Support

Via RHSA-2024:2086 https://access.redhat.com/errata/RHSA-2024:2086