# CVE-2019-1833: Cisco Firepower Threat Defense Software SSL/TLS Policy Bypass Vulnerability

> Remote attackers can bypass SSL/TLS inspection policies in Cisco Firepower Threat Defense by sending malicious TLS messages, allowing uninspected traffic to pass.

- **Severity:** Medium 5.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/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:** 16 May 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-6ffw-22x4-4x3r

## What is CVE-2019-1833?

CVE-2019-1833 is a medium-severity vulnerability in Cisco Secure Firewall Management Center, published on 16 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.

Weakness: CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2019-1833?

It affects 1 product.


Products: Cisco Secure Firewall Management Center.

## How do I fix CVE-2019-1833?

No fix has been published for CVE-2019-1833 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1833 being exploited?

There is no known exploitation of CVE-2019-1833 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Secure Firewall Management Center

- [CVE-2026-20079](https://insights.sbomify.com/CVE-2026-20079/): Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel (critical 10.0, exploited in the wild)
- [CVE-2026-20131](https://insights.sbomify.com/CVE-2026-20131/): Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data (critical 10.0, exploited in the wild)
- [CVE-2026-20316](https://insights.sbomify.com/CVE-2026-20316/): Cisco Secure Firewall Management Center Use of Hard-coded Password (medium 5.3, exploited in the wild)
- [CVE-2025-20265](https://insights.sbomify.com/CVE-2025-20265/): Cisco Secure Firewall Management Center Software Radius Remote Code Execution Vulnerability (critical 10.0)
- [CVE-2024-20424](https://insights.sbomify.com/CVE-2024-20424/): Command injection in Cisco Firepower Management Center (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1833 and fix it if it is affected.

What it is: CVE-2019-1833 is a medium-severity vulnerability in Cisco Secure Firewall Management Center, published on 16 May 2019. 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-2019-1833 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Management Center. 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-2019-1833/ (Markdown: https://insights.sbomify.com/CVE-2019-1833/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1833
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1833
- OSV: https://osv.dev/vulnerability/CVE-2019-1833

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1833/
Summaries are generated and may contain mistakes; the official description above is the record.