# CVE-2019-15261: Cisco Aironet Access Points Point-to-Point Tunneling Protocol Denial of Service Vulnerability

> Remote attackers can crash Cisco Aironet Access Points by sending malicious GRE frames, causing a denial of service for connected clients.

- **Severity:** High 8.6 (`CVSS:3.0/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-3273-9gqr-v74w

## What is CVE-2019-15261?

CVE-2019-15261 is a high-severity denial of service vulnerability in Cisco Aironet Access Point Software, published on 16 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Point-to-Point Tunneling Protocol (PPTP) VPN packet processing functionality in Cisco Aironet Access Points (APs) could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of Generic Routing Encapsulation (GRE) frames that pass through the data plane of an affected AP. An attacker could exploit this vulnerability by associating to a vulnerable AP, initiating a PPTP VPN connection to an arbitrary PPTP VPN server, and sending a malicious GRE frame through the data plane of the AP. A successful exploit could allow the attacker to cause an internal process of the targeted AP to crash, which in turn would cause the AP to reload. The AP reload would cause a DoS condition for clients that are associated with the AP.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-15261?

It affects 3 products.


Products: Cisco Aironet 1810 Firmware, Cisco Aironet 1830 Firmware, Cisco Aironet 1850 Firmware.

## How do I fix CVE-2019-15261?

No fix has been published for CVE-2019-15261 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-15261 being exploited?

There is no known exploitation of CVE-2019-15261 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-15261 and fix it if it is affected.

What it is: CVE-2019-15261 is a high-severity denial of service vulnerability in Cisco Aironet Access Point Software, published on 16 Oct 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-2019-15261 in the wild and no public exploit code.

Affected product: Cisco Aironet Access Point 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-2019-15261/ (Markdown: https://insights.sbomify.com/CVE-2019-15261/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-15261
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-15261
- OSV: https://osv.dev/vulnerability/CVE-2019-15261

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-15261/
Summaries are generated and may contain mistakes; the official description above is the record.