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.
Created grub2 tracking bugs for this issue: Affects: fedora-all [bug 2094468]
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
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
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
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
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
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