A flaw null pointer dereference in the Nitro Enclaves kernel driver was found in the way that Enclaves VMs forces closures on the enclave file descriptor. A local user of a host machine could use this flaw to crash the system or escalate their privileges on the system.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-3543
• https://bugzilla.redhat.com/show_bug.cgi?id=1953022
• https://lore.kernel.org/lkml/20210429165941.27020-1-andraprs@amazon.com/
• https://lore.kernel.org/lkml/20210429165941.27020-2-andraprs@amazon.com/