# CVE-2018-0177: Denial of service in Cisco IOS XE

> Remote attackers can cause denial of service on Cisco Catalyst switches by sending crafted IPv4 packets, leading to high CPU or device reloads.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:** 28 Mar 2018
- **Updated:** 2 Dec 2024
- **Also known as:** GHSA-743q-fpxw-3pxj

## What is CVE-2018-0177?

CVE-2018-0177 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 28 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the IP Version 4 (IPv4) processing code of Cisco IOS XE Software running on Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IPv4 packets. An attacker could exploit this vulnerability by sending specific IPv4 packets to an IPv4 address on an affected device. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. If the switch does not reboot when under attack, it would require manual intervention to reload the device. This vulnerability affects Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches that are running Cisco IOS XE Software Release 16.1.1 or later, until the first fixed release, and are configured with an IPv4 address. Cisco Bug IDs: CSCvd80714.

Weakness: CWE-19

## Which versions are affected by CVE-2018-0177?

It affects 1 product.


Products: Cisco Ios Xe.

## How do I fix CVE-2018-0177?

No fix has been published for CVE-2018-0177 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0177 being exploited?

There is no known exploitation of CVE-2018-0177 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios Xe

- [CVE-2023-20198](https://insights.sbomify.com/CVE-2023-20198/): Cisco IOS XE Web UI Privilege Escalation (critical 10.0, exploited in the wild)
- [CVE-2018-0151](https://insights.sbomify.com/CVE-2018-0151/): Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2023-20273](https://insights.sbomify.com/CVE-2023-20273/): Cisco IOS XE Web UI Command Injection (high 7.2, exploited in the wild)
- [CVE-2025-20188](https://insights.sbomify.com/CVE-2025-20188/): Hardcoded credentials in Cisco IOS XE Software (critical 10.0)
- [CVE-2021-34770](https://insights.sbomify.com/CVE-2021-34770/): Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0177 and fix it if it is affected.

What it is: CVE-2018-0177 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 28 Mar 2018. 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-2018-0177 in the wild and no public exploit code.

Affected product: Cisco Ios Xe. 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-2018-0177/ (Markdown: https://insights.sbomify.com/CVE-2018-0177/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0177
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0177
- OSV: https://osv.dev/vulnerability/CVE-2018-0177

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0177/
Summaries are generated and may contain mistakes; the official description above is the record.