# CVE-2016-6416: Denial of service in n/a

> Remote attackers can cause a denial of service on Cisco Email, Web, and Content Security Appliances by flooding the FTP service with traffic.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2016
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-7cpm-6ch9-5qff

## What is CVE-2016-6416?

CVE-2016-6416 is a medium-severity denial of service vulnerability in Cisco Email Security Appliance, published on 5 Oct 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The FTP service in Cisco AsyncOS on Email Security Appliance (ESA) devices 9.6.0-000 through 9.9.6-026, Web Security Appliance (WSA) devices 9.0.0-162 through 9.5.0-444, and Content Security Management Appliance (SMA) devices allows remote attackers to cause a denial of service via a flood of FTP traffic, aka Bug IDs CSCuz82907, CSCuz84330, and CSCuz86065.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2016-6416?

It affects 3 products.


Products: Cisco Content Security Management Appliance, Cisco Email Security Appliance, Cisco Web Security Appliance.

## How do I fix CVE-2016-6416?

No fix has been published for CVE-2016-6416 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-6416 being exploited?

There is no known exploitation of CVE-2016-6416 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Email Security Appliance

- [CVE-2014-2119](https://insights.sbomify.com/CVE-2014-2119/): File upload in n/a (high 8.5)
- [CVE-2015-6321](https://insights.sbomify.com/CVE-2015-6321/): Denial of service in n/a (high 7.8)
- [CVE-2013-5537](https://insights.sbomify.com/CVE-2013-5537/): Denial of service in n/a (high 7.8)
- [CVE-2016-2183](https://insights.sbomify.com/CVE-2016-2183/): Weak cryptography in n/a (high 7.5)
- [CVE-2013-3395](https://insights.sbomify.com/CVE-2013-3395/): Cross-site request forgery in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-6416 and fix it if it is affected.

What it is: CVE-2016-6416 is a medium-severity denial of service vulnerability in Cisco Email Security Appliance, published on 5 Oct 2016. 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-2016-6416 in the wild and no public exploit code.

Affected product: Cisco Email Security Appliance. 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-2016-6416/ (Markdown: https://insights.sbomify.com/CVE-2016-6416/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-6416
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-6416
- OSV: https://osv.dev/vulnerability/CVE-2016-6416

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-6416/
Summaries are generated and may contain mistakes; the official description above is the record.