# CVE-2013-5211: Denial of service in n/a

> Remote attackers can cause denial of service via traffic amplification using forged monlist requests in the NTP daemon.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jan 2014
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-5211, GHSA-2q29-vhpq-hpv3, MGASA-2014-0032

## What is CVE-2013-5211?

CVE-2013-5211 is a medium-severity denial of service vulnerability in Ntp Ntp, published on 2 Jan 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via forged (1) REQ_MON_GETLIST or (2) REQ_MON_GETLIST_1 requests, as exploited in the wild in December 2013.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2013-5211?

It affects 3 products.


Products: Ntp Ntp, Opensuse Opensuse, Oracle Linux.

## How do I fix CVE-2013-5211?

Upgrade to a fixed version.

## Is CVE-2013-5211 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-5211 exists.

Public exploit code:

- Scans NTP servers for CVE-2013-5211 NTP DDOS amplification vulnerability. (github_poc): https://github.com/dani87/ntpscanner
- PoC for distributed NTP reflection DoS (CVE-2013-5211) (github_poc): https://github.com/sepehrdaddev/ntpdos
- https://github.com/0xhav0c/CVE-2013-5211 (github_poc): https://github.com/0xhav0c/CVE-2013-5211
- NTP monlist scanner CVE-2013-5211 (github_poc): https://github.com/suedadam/ntpscanner
- NTP ntpd monlist Query Reflection - Denial of Service (exploitdb)
- NTP Mode 7 PEER_LIST DoS Scanner (metasploit)

## Other vulnerabilities in Ntp Ntp

- [CVE-2018-12327](https://insights.sbomify.com/CVE-2018-12327/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-6460](https://insights.sbomify.com/CVE-2017-6460/): Memory corruption in n/a (high 8.8)
- [CVE-2019-11331](https://insights.sbomify.com/CVE-2019-11331/): Other in n/a (high 8.1)
- [CVE-2017-6451](https://insights.sbomify.com/CVE-2017-6451/): Memory corruption in n/a (high 7.8)
- [CVE-2017-6452](https://insights.sbomify.com/CVE-2017-6452/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-5211 and fix it if it is affected.

What it is: CVE-2013-5211 is a medium-severity denial of service vulnerability in Ntp Ntp, published on 2 Jan 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-5211 exists.

Affected product: Ntp Ntp. 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-2013-5211/ (Markdown: https://insights.sbomify.com/CVE-2013-5211/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-5211
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-5211
- OSV: https://osv.dev/vulnerability/CVE-2013-5211

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-5211/
Summaries are generated and may contain mistakes; the official description above is the record.