# CVE-2016-4998: Information disclosure in n/a

> Local attackers with container root access can trigger an out-of-bounds read in the Linux kernel netfilter subsystem, potentially exposing sensitive kernel memory or causing a denial of service.

- **Severity:** High 7.1 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:** Yes
- **Published:** 3 Jul 2016
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-4998, GHSA-j87m-7c2j-m929, UBUNTU-CVE-2016-4998

## What is CVE-2016-4998?

CVE-2016-4998 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 3 Jul 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The IPT_SO_SET_REPLACE setsockopt implementation in the netfilter subsystem in the Linux kernel before 4.6 allows local users to cause a denial of service (out-of-bounds read) or possibly obtain sensitive information from kernel heap memory by leveraging in-container root access to provide a crafted offset value that leads to crossing a ruleset blob boundary.

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

## Which versions are affected by CVE-2016-4998?

It affects 3 products.


Products: Canonical Ubuntu Linux, Linux kernel, Oracle Linux.

## How do I fix CVE-2016-4998?

Apply the vendor's patch.

## Is CVE-2016-4998 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-4998 exists.

Public exploit code:

- Linux Kernel 4.6.3 Netfilter Privilege Escalation (metasploit)

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-4998 and fix it if it is affected.

What it is: CVE-2016-4998 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 3 Jul 2016. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-4998 exists.

Affected product: Canonical Ubuntu Linux. 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-2016-4998/ (Markdown: https://insights.sbomify.com/CVE-2016-4998/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-4998
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-4998
- OSV: https://osv.dev/vulnerability/CVE-2016-4998

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-4998/
Summaries are generated and may contain mistakes; the official description above is the record.