# CVE-2002-20001: Denial of service in n/a

> Remote attackers can cause server-side CPU exhaustion by sending invalid Diffie-Hellman public keys, leading to denial of service.

- **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:** Yes
- **Published:** 11 Nov 2021
- **Updated:** 13 Feb 2025
- **Also known as:** GHSA-jx4r-qc68-xjr5, openSUSE-SU-2024:11905-1, openSUSE-SU-2024:13932-1

## What is CVE-2002-20001?

CVE-2002-20001 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 11 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Diffie-Hellman Key Agreement Protocol allows remote attackers (from the client side) to send arbitrary numbers that are actually not public keys, and trigger expensive server-side DHE modular-exponentiation calculations, aka a D(HE)at or D(HE)ater attack. The client needs very little CPU resources and network bandwidth. The attack may be more disruptive in cases where a client can require a server to select its largest supported key size. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2002-20001?

It affects 30 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openssl-1_1` | openSUSE:Tumbleweed | All versions | 1.1.1m-4.1 |
| `ssh-audit` | openSUSE:Tumbleweed | All versions | 3.2.0-1.1 |

Products: Balasys Dheater, F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager, F5 Big-Ip Application Visibility and Reporting, F5 Big-Ip Carrier-Grade Nat, F5 Big-Ip Ddos Hybrid Defender, 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 Service Proxy, F5 Big-Ip Ssl Orchestrator, F5 Big-Ip Webaccelerator and 10 more.

## How do I fix CVE-2002-20001?

Apply the vendor's patch.

## Is CVE-2002-20001 being exploited?

There is no known exploitation of CVE-2002-20001 in the wild and no public exploit code.

Public exploit code:

- D(HE)ater is a proof of concept implementation of the D(HE)at  attack (CVE-2002-20001) through which denial-of-service can be performed by enforcing the Diffie-Hellman key exchange. (read-only clone of the original GitLab project) (github_poc): https://github.com/c0r0n3r/dheater
- POC for Testing the Existence of D(HE)at DOS Attack for (CVE-2002-20001) (github_poc): https://github.com/itmaniac/dheat_dos_attack_poc

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2002-20001 and fix it if it is affected.

What it is: CVE-2002-20001 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 11 Nov 2021. 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-2002-20001 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-2002-20001/ (Markdown: https://insights.sbomify.com/CVE-2002-20001/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2002-20001
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2002-20001
- OSV: https://osv.dev/vulnerability/CVE-2002-20001

---
From sbomify Insights: https://insights.sbomify.com/CVE-2002-20001/
Summaries are generated and may contain mistakes; the official description above is the record.