# CVE-2018-0241: Denial of service in Cisco IOS XR

> An unauthenticated adjacent attacker can cause a denial of service on Cisco IOS XR devices by sending UDP broadcast packets when an IPv4 helper address is configured.

- **Severity:** High 7.4 (`CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Apr 2018
- **Updated:** 29 Nov 2024
- **Also known as:** GHSA-73pp-cff4-vg2v

## What is CVE-2018-0241?

CVE-2018-0241 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 19 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the UDP broadcast forwarding function of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to improper handling of UDP broadcast packets that are forwarded to an IPv4 helper address. An attacker could exploit this vulnerability by sending multiple UDP broadcast packets to the affected device. An exploit could allow the attacker to cause a buffer leak on the affected device, eventually resulting in a DoS condition requiring manual intervention to recover. This vulnerability affects all Cisco IOS XR platforms running 6.3.1, 6.2.3, or earlier releases of Cisco IOS XR Software when at least one IPv4 helper address is configured on an interface of the device. Cisco Bug IDs: CSCvi35625.

Weakness: CWE-399

## Which versions are affected by CVE-2018-0241?

It affects 1 product.


Products: Cisco Ios Xr.

## How do I fix CVE-2018-0241?

No fix has been published for CVE-2018-0241 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0241 being exploited?

There is no known exploitation of CVE-2018-0241 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios Xr

- [CVE-2020-3118](https://insights.sbomify.com/CVE-2020-3118/): Cisco IOS XR Software Discovery Protocol Format String (high 8.8, exploited in the wild)
- [CVE-2020-3569](https://insights.sbomify.com/CVE-2020-3569/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2020-3566](https://insights.sbomify.com/CVE-2020-3566/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2010-3035](https://insights.sbomify.com/CVE-2010-3035/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (high 7.5, exploited in the wild)
- [CVE-2022-20821](https://insights.sbomify.com/CVE-2022-20821/): Cisco IOS XR Open Port (medium 6.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0241 and fix it if it is affected.

What it is: CVE-2018-0241 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 19 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-0241 in the wild and no public exploit code.

Affected product: Cisco Ios Xr. 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-2018-0241/ (Markdown: https://insights.sbomify.com/CVE-2018-0241/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0241
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0241
- OSV: https://osv.dev/vulnerability/CVE-2018-0241

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0241/
Summaries are generated and may contain mistakes; the official description above is the record.