# CVE-2022-20940: Weak cryptography in Cisco Firepower Threat Defense Software

> An unauthenticated remote attacker can decrypt previously captured TLS sessions by exploiting a Bleichenbacher attack vulnerability in the TLS handler.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Nov 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-xqwj-v278-6v7x

## What is CVE-2022-20940?

CVE-2022-20940 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 10 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the TLS handler of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to gain access to sensitive information.

 This vulnerability is due to improper implementation of countermeasures against a Bleichenbacher attack on a device that uses SSL decryption policies. An attacker could exploit this vulnerability by sending crafted TLS messages to an affected device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack. A successful exploit could allow the attacker to perform cryptanalytic operations that may allow decryption of previously captured TLS sessions to the affected device.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2022-20940?

It affects 1 product.


Products: Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2022-20940?

No fix has been published for CVE-2022-20940 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-20940 being exploited?

There is no known exploitation of CVE-2022-20940 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Secure Firewall Threat Defense

- [CVE-2024-20412](https://insights.sbomify.com/CVE-2024-20412/): Hardcoded credentials in Cisco Firepower Threat Defense Software (critical 9.3)
- [CVE-2024-20330](https://insights.sbomify.com/CVE-2024-20330/): Memory corruption in Cisco Firepower Threat Defense Software (high 8.6)
- [CVE-2024-20339](https://insights.sbomify.com/CVE-2024-20339/): Cisco Firepower Threat Defense Software for Firepower 2100 Series TLS Denial of Service Vulnerability (high 8.6)
- [CVE-2024-20351](https://insights.sbomify.com/CVE-2024-20351/): Cisco Firepower Threat Defense Software Snort Firewall Denial of Service Vulnerability (high 8.6)
- [CVE-2023-20083](https://insights.sbomify.com/CVE-2023-20083/): Denial of service in Cisco Firepower Threat Defense Software (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-20940 and fix it if it is affected.

What it is: CVE-2022-20940 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 10 Nov 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-2022-20940 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Threat Defense. 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-2022-20940/ (Markdown: https://insights.sbomify.com/CVE-2022-20940/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-20940
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-20940
- OSV: https://osv.dev/vulnerability/CVE-2022-20940

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-20940/
Summaries are generated and may contain mistakes; the official description above is the record.