# CVE-2018-0484: Cisco IOS and IOS XE Software Secure Shell Connection on VRF Vulnerability

> Attackers can bypass SSH access controls to connect from VRF instances, though valid credentials are still required for full access.

- **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:** 10 Jan 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-wpcx-9mmv-mm42

## What is CVE-2018-0484?

CVE-2018-0484 is a medium-severity authentication bypass vulnerability in Cisco Ios, published on 10 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the access control logic of the Secure Shell (SSH) server of Cisco IOS and IOS XE Software may allow connections sourced from a virtual routing and forwarding (VRF) instance despite the absence of the vrf-also keyword in the access-class configuration. The vulnerability is due to a missing check in the SSH server. An attacker could use this vulnerability to open an SSH connection to an affected Cisco IOS or IOS XE device with a source address belonging to a VRF instance. Once connected, the attacker would still need to provide valid credentials to access the device.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2018-0484?

It affects 1 product.


Products: Cisco Ios.

## How do I fix CVE-2018-0484?

No fix has been published for CVE-2018-0484 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0484 being exploited?

There is no known exploitation of CVE-2018-0484 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios

- [CVE-2017-12240](https://insights.sbomify.com/CVE-2017-12240/): Cisco IOS and IOS XE Software DHCP Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-3881](https://insights.sbomify.com/CVE-2017-3881/): Cisco IOS and IOS XE Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2018-0167](https://insights.sbomify.com/CVE-2018-0167/): Cisco IOS, XR, and XE Software Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2017-6736](https://insights.sbomify.com/CVE-2017-6736/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-6737](https://insights.sbomify.com/CVE-2017-6737/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0484 and fix it if it is affected.

What it is: CVE-2018-0484 is a medium-severity authentication bypass vulnerability in Cisco Ios, published on 10 Jan 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-2018-0484 in the wild and no public exploit code.

Affected product: Cisco Ios. 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-2018-0484/ (Markdown: https://insights.sbomify.com/CVE-2018-0484/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0484
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0484
- OSV: https://osv.dev/vulnerability/CVE-2018-0484

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-0484/
Summaries are generated and may contain mistakes; the official description above is the record.