As per upstream: The handlers for the RecordCreateContext and RecordRegisterClients requests of the Record extension do not properly validate the request length leading to out of bounds memory write.
Created xorg-x11-server tracking bugs for this issue: Affects: fedora-all [bug 2032945]
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2022:0003 https://access.redhat.com/errata/RHSA-2022:0003
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-2021-4011
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2022:1917 https://access.redhat.com/errata/RHSA-2022:1917