# CVE-2016-1886: Integer overflow in n/a

> Local attackers can exploit an integer signedness error in the FreeBSD kernel to gain privileges or cause a denial of service via a crafted ioctl call.

- **Severity:** High 7.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 May 2016
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-3pmm-q6gm-q5rg

## What is CVE-2016-1886?

CVE-2016-1886 is a high-severity vulnerability in Freebsd Freebsd, published on 25 May 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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."

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2016-1886?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2016-1886?

No fix has been published for CVE-2016-1886 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-1886 being exploited?

There is no known exploitation of CVE-2016-1886 in the wild and no public exploit code.

Public exploit code:

- FreeBSD Kernel (FreeBSD 10.2 < 10.3 x64) - 'SETFKEY' (PoC) (exploitdb)

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-1886 and fix it if it is affected.

What it is: CVE-2016-1886 is a high-severity vulnerability in Freebsd Freebsd, published on 25 May 2016. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-1886 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2016-1886/ (Markdown: https://insights.sbomify.com/CVE-2016-1886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-1886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-1886
- OSV: https://osv.dev/vulnerability/CVE-2016-1886

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-1886/
Summaries are generated and may contain mistakes; the official description above is the record.