# CVE-2022-23021: Null dereference in BIG-IP

> Attackers can cause a denial of service by triggering a null dereference in TMM when specific virtual server configurations are enabled.

- **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:** 25 Jan 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-w343-x6rw-f2x7

## What is CVE-2022-23021?

CVE-2022-23021 is a high-severity vulnerability in F5 Big-Ip Access Policy Manager, published on 25 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

On BIG-IP version 16.1.x before 16.1.2, when any of the following configurations are configured on a virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate: HTTP redirect rule in an LTM policy, BIG-IP APM Access Profile, and Explicit HTTP Proxy in HTTP Profile. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-23021?

It affects 11 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 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.

## How do I fix CVE-2022-23021?

No fix has been published for CVE-2022-23021 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-23021 being exploited?

There is no known exploitation of CVE-2022-23021 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-2022-23021 and fix it if it is affected.

What it is: CVE-2022-23021 is a high-severity vulnerability in F5 Big-Ip Access Policy Manager, published on 25 Jan 2022. 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-2022-23021 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-2022-23021/ (Markdown: https://insights.sbomify.com/CVE-2022-23021/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-23021
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-23021
- OSV: https://osv.dev/vulnerability/CVE-2022-23021

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-23021/
Summaries are generated and may contain mistakes; the official description above is the record.