# CVE-2018-0247: Auth bypass in Cisco Wireless LAN Controller and Aironet Access Points

> Unauthenticated adjacent attackers can bypass WebAuth and access local network resources in specific FlexConnect NAT configurations on Cisco WLC and Aironet APs.

- **Severity:** Medium 4.7 (`CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **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:** 2 May 2018
- **Updated:** 29 Nov 2024
- **Also known as:** GHSA-f75h-vqxj-crqh

## What is CVE-2018-0247?

CVE-2018-0247 is a medium-severity authentication bypass vulnerability in Cisco Wireless Lan Controller Software, published on 2 May 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in Web Authentication (WebAuth) clients for the Cisco Wireless LAN Controller (WLC) and Aironet Access Points running Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass traffic. The vulnerability is due to incorrect implementation of authentication for WebAuth clients in a specific configuration. An attacker could exploit this vulnerability by sending traffic to local network resources without having gone through authentication. A successful exploit could allow the attacker to bypass authentication and pass traffic. This affects Cisco Aironet Access Points running Cisco IOS Software and Cisco Wireless LAN Controller (WLC) releases prior to 8.5.110.0 for the following specific WLC configuration only: (1) The Access Point (AP) is configured in FlexConnect Mode with NAT. (2) The WLAN is configured for central switching, meaning the client is being assigned a unique IP address. (3) The AP is configured with a Split Tunnel access control list (ACL) for access to local network resources, meaning the AP is doing the NAT on the connection. (4) The client is using WebAuth. This vulnerability does not apply to .1x clients in the same configuration. Cisco Bug IDs: CSCvc79502, CSCvf71789.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2018-0247?

It affects 2 products.


Products: Cisco Aironet Access Point Software, Cisco Wireless Lan Controller Software.

## How do I fix CVE-2018-0247?

No fix has been published for CVE-2018-0247 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0247 being exploited?

There is no known exploitation of CVE-2018-0247 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Wireless Lan Controller Software

- [CVE-2017-3831](https://insights.sbomify.com/CVE-2017-3831/): Auth bypass in Cisco Mobility Express 1800 Access Point Series (critical 9.8)
- [CVE-2022-20622](https://insights.sbomify.com/CVE-2022-20622/): Cisco Embedded Wireless Controller with Catalyst Access Points IP Flood Denial of Service Vulnerability (high 8.6)
- [CVE-2018-0234](https://insights.sbomify.com/CVE-2018-0234/): Denial of service in Cisco Aironet 1810, 1830, and 1850 Series Access Points (high 8.6)
- [CVE-2016-1419](https://insights.sbomify.com/CVE-2016-1419/): Denial of service in n/a (high 8.1)
- [CVE-2016-6362](https://insights.sbomify.com/CVE-2016-6362/): Privilege escalation in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0247 and fix it if it is affected.

What it is: CVE-2018-0247 is a medium-severity authentication bypass vulnerability in Cisco Wireless Lan Controller Software, published on 2 May 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-2018-0247 in the wild and no public exploit code.

Affected product: Cisco Wireless Lan Controller Software. 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-2018-0247/ (Markdown: https://insights.sbomify.com/CVE-2018-0247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0247
- OSV: https://osv.dev/vulnerability/CVE-2018-0247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0247/
Summaries are generated and may contain mistakes; the official description above is the record.