# CVE-2020-5947: Information disclosure in BIG-IP 2000 series (C112), BIG-IP 4000 series (C113), BIG-IP i2000 series (C117), BIG-IP i4000 series (C115), BIG-IP Virtual Edition (VE)

> Attackers can obtain TCP sequence numbers from specific BIG-IP platforms, potentially allowing connection hijacking or spoofing.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-253r-3vgg-gj92

## What is CVE-2020-5947?

CVE-2020-5947 is a medium-severity vulnerability in F5 Big-Ip Access Policy Manager, published on 19 Nov 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In versions 16.0.0-16.0.0.1 and 15.1.0-15.1.1, on specific BIG-IP platforms, attackers may be able to obtain TCP sequence numbers from the BIG-IP system that can be reused in future connections with the same source and destination port and IP numbers. Only these platforms are affected: BIG-IP 2000 series (C112), BIG-IP 4000 series (C113), BIG-IP i2000 series (C117), BIG-IP i4000 series (C115), BIG-IP Virtual Edition (VE).

## Which versions are affected by CVE-2020-5947?

It affects 14 products.


Products: 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 Ddos Hybrid Defender, 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, F5 Ssl Orchestrator.

## How do I fix CVE-2020-5947?

No fix has been published for CVE-2020-5947 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-5947 being exploited?

There is no known exploitation of CVE-2020-5947 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-2020-5947 and fix it if it is affected.

What it is: CVE-2020-5947 is a medium-severity vulnerability in F5 Big-Ip Access Policy Manager, published on 19 Nov 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-5947 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-2020-5947/ (Markdown: https://insights.sbomify.com/CVE-2020-5947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5947
- OSV: https://osv.dev/vulnerability/CVE-2020-5947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5947/
Summaries are generated and may contain mistakes; the official description above is the record.