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

> An adjacent attacker can bypass Layer 2 filters to send crafted packets directly to the kernel of Cisco ASA or FTD devices.

- **Severity:** Medium 4.3 (`CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 May 2019
- **Updated:** 21 Nov 2024
- **Also known as:** GHSA-96r8-3qv9-q756

## What is CVE-2019-1695?

CVE-2019-1695 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 3 May 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2019-1695?

It affects 2 products.


Products: Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2019-1695?

No fix has been published for CVE-2019-1695 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1695 being exploited?

There is no known exploitation of CVE-2019-1695 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Adaptive Security Appliance Software

- [CVE-2025-20333](https://insights.sbomify.com/CVE-2025-20333/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow (critical 9.9, exploited in the wild)
- [CVE-2016-6366](https://insights.sbomify.com/CVE-2016-6366/): Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2026-20349](https://insights.sbomify.com/CVE-2026-20349/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection (high 8.6, exploited in the wild)
- [CVE-2024-20353](https://insights.sbomify.com/CVE-2024-20353/): Cisco ASA and FTD Denial of Service (high 8.6, exploited in the wild)
- [CVE-2016-6367](https://insights.sbomify.com/CVE-2016-6367/): Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1695 and fix it if it is affected.

What it is: CVE-2019-1695 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 3 May 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-1695 in the wild and no public exploit code.

Affected product: Cisco Adaptive Security Appliance Software. 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-2019-1695/ (Markdown: https://insights.sbomify.com/CVE-2019-1695/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1695
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1695
- OSV: https://osv.dev/vulnerability/CVE-2019-1695

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1695/
Summaries are generated and may contain mistakes; the official description above is the record.