# CVE-2019-6611: Denial of service in BIG-IP (LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, FPS, GTM, Link Controller, PEM, WebAccelerator)

> Attackers can cause a denial of service by sending rare PPTP traffic sequences to BIG-IP systems configured with CGNAT and PPTP profiles.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:** 3 May 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-cm77-cg9p-x2w6

## What is CVE-2019-6611?

CVE-2019-6611 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 3 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When BIG-IP 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, 12.1.0-12.1.4, 11.6.1-11.6.3.4, and 11.5.2-11.5.8 are processing certain rare data sequences occurring in PPTP VPN traffic, the BIG-IP system may execute incorrect logic. The TMM may restart and produce a core file as a result of this condition. The BIG-IP system provisioned with the CGNAT module and configured with a virtual server using a PPTP profile is exposed to this vulnerability.

## Which versions are affected by CVE-2019-6611?

It affects 13 products.


Products: F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager, F5 Big-Ip Domain Name System, F5 Big-Ip Edge Gateway, F5 Big-Ip Fraud Protection Service, F5 Big-Ip Global Traffic Manager, F5 Big-Ip Link Controller, F5 Big-Ip Local Traffic Manager, F5 Big-Ip Policy Enforcement Manager, F5 Big-Ip Webaccelerator.

## How do I fix CVE-2019-6611?

No fix has been published for CVE-2019-6611 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-6611 being exploited?

There is no known exploitation of CVE-2019-6611 in the wild and no public exploit code.

## Other vulnerabilities in F5 Big-Ip Access Policy Manager

- [CVE-2023-46747](https://insights.sbomify.com/CVE-2023-46747/): F5 BIG-IP Configuration Utility Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2022-1388](https://insights.sbomify.com/CVE-2022-1388/): F5 BIG-IP Missing Authentication (critical 9.8, exploited in the wild)
- [CVE-2021-22986](https://insights.sbomify.com/CVE-2021-22986/): F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2021-22991](https://insights.sbomify.com/CVE-2021-22991/): F5 BIG-IP Traffic Management Microkernel Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2020-5902](https://insights.sbomify.com/CVE-2020-5902/): F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6611 and fix it if it is affected.

What it is: CVE-2019-6611 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 3 May 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-2019-6611 in the wild and no public exploit code.

Affected product: F5 Big-Ip Access Policy Manager. 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-2019-6611/ (Markdown: https://insights.sbomify.com/CVE-2019-6611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6611
- OSV: https://osv.dev/vulnerability/CVE-2019-6611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-6611/
Summaries are generated and may contain mistakes; the official description above is the record.