# CVE-2019-1814: Cisco Small Business 300 Series Managed Switches DHCP Denial of Service Vulnerability

> An unauthenticated remote attacker can cause a denial of service on Cisco Small Business 300 Series switches by sending crafted DHCP packets that exhaust system memory.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 May 2019
- **Updated:** 21 Nov 2024
- **Also known as:** GHSA-r8m5-hhgx-g34x

## What is CVE-2019-1814?

CVE-2019-1814 is a medium-severity denial of service vulnerability in Cisco Small Business 300 Series Managed Switches, published on 15 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the interactions between the DHCP and TFTP features for Cisco Small Business 300 Series (Sx300) Managed Switches could allow an unauthenticated, remote attacker to cause the device to become low on system memory, which in turn could lead to an unexpected reload of the device and result in a denial of service (DoS) condition on an affected device. The vulnerability is due to a failure to free system memory when an unexpected DHCP request is received. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the targeted device. A successful exploit could allow the attacker to cause an unexpected reload of the device.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-1814?

It affects 27 products.


Products: Cisco Sf300-08 Firmware, Cisco Sf300-24 Firmware, Cisco Sf300-24mp Firmware, Cisco Sf300-24p Firmware, Cisco Sf300-24pp Firmware, Cisco Sf300-48 Firmware, Cisco Sf300-48p Firmware, Cisco Sf300-48pp Firmware, Cisco Sf302-08 Firmware, Cisco Sf302-08mp Firmware, Cisco Sf302-08mpp Firmware, Cisco Sf302-08p Firmware, Cisco Sf302-08pp Firmware, Cisco Sg300-10 Firmware, Cisco Sg300-10mp Firmware, Cisco Sg300-10mpp Firmware, Cisco Sg300-10p Firmware, Cisco Sg300-10pp Firmware, Cisco Sg300-10sfp Firmware, Cisco Sg300-20 Firmware and 7 more.

## How do I fix CVE-2019-1814?

No fix has been published for CVE-2019-1814 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1814 being exploited?

There is no known exploitation of CVE-2019-1814 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Small Business 300 Series Managed Switches

- [CVE-2020-3147](https://insights.sbomify.com/CVE-2020-3147/): Cisco Small Business Switches Denial of Service Vulnerability (high 8.6)
- [CVE-2018-0465](https://insights.sbomify.com/CVE-2018-0465/): Cisco Small Business 300 Series Managed Switches Cross-Site Scripting Vulnerability (medium 6.1)
- [CVE-2018-0407](https://insights.sbomify.com/CVE-2018-0407/): Cross-site scripting in Cisco Small Business 300 Series Managed Switches unknown (medium 5.4)
- [CVE-2018-0408](https://insights.sbomify.com/CVE-2018-0408/): Cross-site scripting in Cisco Small Business 300 Series Managed Switches unknown (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1814 and fix it if it is affected.

What it is: CVE-2019-1814 is a medium-severity denial of service vulnerability in Cisco Small Business 300 Series Managed Switches, published on 15 May 2019. 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-2019-1814 in the wild and no public exploit code.

Affected product: Cisco Small Business 300 Series Managed Switches. 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-2019-1814/ (Markdown: https://insights.sbomify.com/CVE-2019-1814/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1814
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1814
- OSV: https://osv.dev/vulnerability/CVE-2019-1814

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1814/
Summaries are generated and may contain mistakes; the official description above is the record.