CVE-2021-3543

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.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://bugzilla.redhat.com/show_bug.cgi?id=1953022
• https://lore.kernel.org/lkml/20210429165941.27020-2-andraprs%40amazon.com/
• https://bugzilla.redhat.com/show_bug.cgi?id=1953022
• https://lore.kernel.org/lkml/20210429165941.27020-2-andraprs%40amazon.com/