# CVE-2018-5541: Denial of service in BIG-IP (ASM)

> Attackers can cause excessive CPU usage and denial of service in F5 BIG-IP ASM by sending HTTP requests with an unusually large number of parameters.

- **Severity:** High 7.5 (`CVSS:3.0/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:** 25 Jul 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-r9ff-j36c-4rfp

## What is CVE-2018-5541?

CVE-2018-5541 is a high-severity denial of service vulnerability in F5 Big-Ip Application Security Manager, published on 25 Jul 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When F5 BIG-IP ASM 13.0.0-13.1.0.1, 12.1.0-12.1.3.5, 11.6.0-11.6.3.1, or 11.5.1-11.5.6 is processing HTTP requests, an unusually large number of parameters can cause excessive CPU usage in the BIG-IP ASM bd process.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2018-5541?

It affects 1 product.


Products: F5 Big-Ip Application Security Manager.

## How do I fix CVE-2018-5541?

No fix has been published for CVE-2018-5541 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-5541 being exploited?

There is no known exploitation of CVE-2018-5541 in the wild and no public exploit code.

## Other vulnerabilities in F5 Big-Ip Application Security Manager

- [CVE-2019-6665](https://insights.sbomify.com/CVE-2019-6665/): Other in BIG-IP ASM (critical 9.4)
- [CVE-2019-6650](https://insights.sbomify.com/CVE-2019-6650/): Information disclosure in BIG-IP ASM (critical 9.1)
- [CVE-2025-24326](https://insights.sbomify.com/CVE-2025-24326/): BIG-IP Advanced WAF/ASM BADoS vulnerability (high 8.9)
- [CVE-2025-55669](https://insights.sbomify.com/CVE-2025-55669/): BIG-IP HTTP/2 vulnerability (high 8.7)
- [CVE-2009-4420](https://insights.sbomify.com/CVE-2009-4420/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-5541 and fix it if it is affected.

What it is: CVE-2018-5541 is a high-severity denial of service vulnerability in F5 Big-Ip Application Security Manager, published on 25 Jul 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-2018-5541 in the wild and no public exploit code.

Affected product: F5 Big-Ip Application Security 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-2018-5541/ (Markdown: https://insights.sbomify.com/CVE-2018-5541/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-5541
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-5541
- OSV: https://osv.dev/vulnerability/CVE-2018-5541

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-5541/
Summaries are generated and may contain mistakes; the official description above is the record.