# CVE-2017-12218: Security feature bypass in Cisco Email Security Appliance

> An unauthenticated remote attacker can bypass malware scanning on Cisco Email Security Appliances by sending crafted EML attachments, delivering malware to end users.

- **Severity:** Medium 5.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-rwch-g2hc-94xv

## What is CVE-2017-12218?

CVE-2017-12218 is a medium-severity vulnerability in Cisco Asyncos, published on 7 Sep 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the malware detection functionality within Advanced Malware Protection (AMP) of Cisco AsyncOS Software for Cisco Email Security Appliances (ESAs) could allow an unauthenticated, remote attacker to cause an email attachment containing malware to be delivered to the end user. The vulnerability is due to the failure of AMP to scan certain EML attachments that could contain malware. An attacker could exploit this vulnerability by sending an email with a crafted EML attachment through the targeted device. A successful exploit could allow the attacker to bypass the configured ESA email message and content filtering and allow the malware to be delivered to the end user. Vulnerable Products: This vulnerability affects Cisco AsyncOS Software for Cisco ESA, both virtual and hardware appliances, that are configured with message or content filters to scan incoming email attachments on the ESA. Cisco Bug IDs: CSCuz81533.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-12218?

It affects 1 product.


Products: Cisco Asyncos.

## How do I fix CVE-2017-12218?

No fix has been published for CVE-2017-12218 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-12218 being exploited?

There is no known exploitation of CVE-2017-12218 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Asyncos

- [CVE-2025-20393](https://insights.sbomify.com/CVE-2025-20393/): Cisco Multiple Products Improper Input Validation (critical 10.0, exploited in the wild)
- [CVE-2026-76519](https://insights.sbomify.com/CVE-2026-76519/): Cisco Secure Email Gateway Relative Path Traversal (critical 9.8, exploited in the wild)
- [CVE-2026-76461](https://insights.sbomify.com/CVE-2026-76461/): Cisco Secure Email Gateway SQL Injection (critical 9.8, exploited in the wild)
- [CVE-2024-20435](https://insights.sbomify.com/CVE-2024-20435/): Command injection in Cisco Secure Web Appliance (high 8.8)
- [CVE-2019-15956](https://insights.sbomify.com/CVE-2019-15956/): Cisco Web Security Appliance Unauthorized Device Reset Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-12218 and fix it if it is affected.

What it is: CVE-2017-12218 is a medium-severity vulnerability in Cisco Asyncos, published on 7 Sep 2017. 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-2017-12218 in the wild and no public exploit code.

Affected product: Cisco Asyncos. 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-2017-12218/ (Markdown: https://insights.sbomify.com/CVE-2017-12218/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-12218
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-12218
- OSV: https://osv.dev/vulnerability/CVE-2017-12218

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-12218/
Summaries are generated and may contain mistakes; the official description above is the record.