# CVE-2018-0203: Other in Cisco Unity Connection

> Unauthenticated remote attackers can exploit improper domain handling to send unsolicited email messages via the SMTP relay.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Feb 2018
- **Updated:** 2 Dec 2024
- **Also known as:** GHSA-g977-q8vq-h243

## What is CVE-2018-0203?

CVE-2018-0203 is a medium-severity vulnerability in Cisco Unity Connection, published on 22 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the SMTP relay of Cisco Unity Connection could allow an unauthenticated, remote attacker to send unsolicited email messages, aka a Mail Relay Vulnerability. The vulnerability is due to improper handling of domain information in the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted requests to the targeted application. A successful exploit could allow the attacker to send email messages to arbitrary addresses. Cisco Bug IDs: CSCvg62215.

Weakness: CWE-19

## Which versions are affected by CVE-2018-0203?

It affects 1 product.


Products: Cisco Unity Connection.

## How do I fix CVE-2018-0203?

No fix has been published for CVE-2018-0203 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0203 being exploited?

There is no known exploitation of CVE-2018-0203 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Unity Connection

- [CVE-2014-3333](https://insights.sbomify.com/CVE-2014-3333/): Privilege escalation in n/a (critical 9.0)
- [CVE-2012-0366](https://insights.sbomify.com/CVE-2012-0366/): Privilege escalation in n/a (critical 9.0)
- [CVE-2026-20034](https://insights.sbomify.com/CVE-2026-20034/): Cisco Unity Connection Remote Code Execution Vulnerability (high 8.8)
- [CVE-2012-3060](https://insights.sbomify.com/CVE-2012-3060/): Denial of service in n/a (high 7.8)
- [CVE-2012-0367](https://insights.sbomify.com/CVE-2012-0367/): Denial of service in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0203 and fix it if it is affected.

What it is: CVE-2018-0203 is a medium-severity vulnerability in Cisco Unity Connection, published on 22 Feb 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-2018-0203 in the wild and no public exploit code.

Affected product: Cisco Unity Connection. 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-2018-0203/ (Markdown: https://insights.sbomify.com/CVE-2018-0203/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0203
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0203
- OSV: https://osv.dev/vulnerability/CVE-2018-0203

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0203/
Summaries are generated and may contain mistakes; the official description above is the record.