# CVE-2016-2518: Memory corruption in n/a

> Remote attackers can cause an out-of-bounds reference and denial of service in NTP servers via a crafted addpeer request with a large hmode value.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jan 2017
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-2518, GHSA-9cgg-qq3h-mgcv, UBUNTU-CVE-2016-2518

## What is CVE-2016-2518?

CVE-2016-2518 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 30 Jan 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The MATCH_ASSOC function in NTP before version 4.2.8p9 and 4.3.x before 4.3.92 allows remote attackers to cause an out-of-bounds reference via an addpeer request with a large hmode value.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2016-2518?

It affects 17 products.


Products: Debian Debian Linux, Freebsd Freebsd, Netapp Clustered Data Ontap, Netapp Data Ontap, Netapp Oncommand Balance, Netapp Oncommand Performance Manager, Netapp Oncommand Unified Manager for Clustered Data Ontap, Ntp Ntp, Oracle Communications User Data Repository, Oracle Linux, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Workstation, Siemens Simatic Net Cp 443-1 Opc Ua Firmware.

## How do I fix CVE-2016-2518?

Upgrade to a fixed version.

## Is CVE-2016-2518 being exploited?

There is no known exploitation of CVE-2016-2518 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-2518 and fix it if it is affected.

What it is: CVE-2016-2518 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 30 Jan 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-2518 in the wild and no public exploit code.

Affected product: Debian Debian 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-2016-2518/ (Markdown: https://insights.sbomify.com/CVE-2016-2518/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-2518
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-2518
- OSV: https://osv.dev/vulnerability/CVE-2016-2518

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-2518/
Summaries are generated and may contain mistakes; the official description above is the record.