# CVE-2017-6657: Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation.


- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 16 May 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-h9jm-vc47-2v23

## What is CVE-2017-6657?

CVE-2017-6657 is a high-severity vulnerability in Snort 3.0 All versions prior to build 233., published on 16 May 2017. 

### Official description

Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation. Since valid ether type and IP protocol numbers do not overlap, Snort++ stores all protocol decoders in a single array. That makes it possible to craft packets that have IP protocol numbers in the ether type field which will confuse the Snort++ decoder. For example, an eth:llc:snap:icmp6 packet will cause a crash because there is no ip6 header with which to calculate the icmp6 checksum. Affected decoders include gre, llc, trans_bridge, ciscometadata, linux_sll, and token_ring. The fix adds a check in the packet manager to validate the ether type before indexing the decoder array. An out of range ether type will raise 116:473.

## Which versions are affected by CVE-2017-6657?

It affects 1 product.


Products: Cisco Snort\+\+.

## How do I fix CVE-2017-6657?

No fix has been published for CVE-2017-6657 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-6657 being exploited?

There is no known exploitation of CVE-2017-6657 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6657 and fix it if it is affected.

What it is: CVE-2017-6657 is a high-severity vulnerability in Snort 3.0 All versions prior to build 233., published on 16 May 2017. 
Exploitation: There is no known exploitation of CVE-2017-6657 in the wild and no public exploit code.

Affected product: Snort 3.0 All versions prior to build 233.. 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-2017-6657/ (Markdown: https://insights.sbomify.com/CVE-2017-6657/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6657
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6657
- OSV: https://osv.dev/vulnerability/CVE-2017-6657

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-6657/
Summaries are generated and may contain mistakes; the official description above is the record.