# CVE-2016-6465: Security feature bypass in Cisco AsyncOS

> Unauthenticated attackers can bypass content filters on Cisco Email and Web Security Appliances if scanning services are enabled.

- **Severity:** Medium 4.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Dec 2016
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-wff9-q6wf-8f5q

## What is CVE-2016-6465?

CVE-2016-6465 is a medium-severity vulnerability in Cisco Email Security Appliance, published on 14 Dec 2016. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A vulnerability in the content filtering functionality of Cisco AsyncOS Software for Cisco Email Security Appliances and Cisco Web Security Appliances could allow an unauthenticated, remote attacker to bypass user filters that are configured for an affected device. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for both virtual and hardware versions of the following Cisco products: Cisco Email Security Appliances (ESAs) that are configured to use message or content filters that scan incoming email attachments; Cisco Web Security Appliances (WSAs) that are configured to use services that scan accessed web content. More Information: CSCva90076, CSCvb06764. Known Affected Releases: 10.0.0-125 8.5.7-042 9.7.2-047.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-6465?

It affects 1 product.


Products: Cisco Email Security Appliance.

## How do I fix CVE-2016-6465?

No fix has been published for CVE-2016-6465 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-6465 being exploited?

There is no known exploitation of CVE-2016-6465 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Email Security Appliance

- [CVE-2022-20798](https://insights.sbomify.com/CVE-2022-20798/): Cisco Email Security Appliance and Cisco Secure Email and Web Manager External Authentication Bypass Vulnerability (critical 9.8)
- [CVE-2015-6291](https://insights.sbomify.com/CVE-2015-6291/): Denial of service in n/a (high 7.8)
- [CVE-2022-20664](https://insights.sbomify.com/CVE-2022-20664/): Cisco Email Security Appliance and Cisco Secure Email and Web Manager Information Disclosure Vulnerability (high 7.7)
- [CVE-2022-20960](https://insights.sbomify.com/CVE-2022-20960/): Denial of service in Cisco Secure Email (high 7.5)
- [CVE-2018-0419](https://insights.sbomify.com/CVE-2018-0419/): Security feature bypass in Email Security Appliance (ESA) (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-6465 and fix it if it is affected.

What it is: CVE-2016-6465 is a medium-severity vulnerability in Cisco Email Security Appliance, published on 14 Dec 2016. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2016-6465 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-2016-6465/ (Markdown: https://insights.sbomify.com/CVE-2016-6465/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-6465
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-6465
- OSV: https://osv.dev/vulnerability/CVE-2016-6465

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-6465/
Summaries are generated and may contain mistakes; the official description above is the record.