# CVE-2017-6656: Denial of service in Cisco IP Phone 8800 Series

> Unauthenticated remote attackers can cause a denial of service on Cisco IP Phones by triggering a SIP process restart, dropping all active calls.

- **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:** 13 Jun 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-g24g-3vhv-96p3

## What is CVE-2017-6656?

CVE-2017-6656 is a medium-severity denial of service vulnerability in Cisco IP Phone 8800 Series, published on 13 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in Session Initiation Protocol (SIP) call handling of Cisco IP Phone 8800 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the SIP process unexpectedly restarting. All active phone calls are dropped as the SIP process restarts. More Information: CSCvc29353. Known Affected Releases: 11.0(0.1). Known Fixed Releases: 11.0(0)MP2.153 11.0(0)MP2.62.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-6656?

It affects 1 product.


Products: Cisco Ip Phone 8800 Series.

## How do I fix CVE-2017-6656?

No fix has been published for CVE-2017-6656 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-6656 being exploited?

There is no known exploitation of CVE-2017-6656 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6656 and fix it if it is affected.

What it is: CVE-2017-6656 is a medium-severity denial of service vulnerability in Cisco IP Phone 8800 Series, published on 13 Jun 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-2017-6656 in the wild and no public exploit code.

Affected product: Cisco IP Phone 8800 Series. 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-2017-6656/ (Markdown: https://insights.sbomify.com/CVE-2017-6656/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6656
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6656
- OSV: https://osv.dev/vulnerability/CVE-2017-6656

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-6656/
Summaries are generated and may contain mistakes; the official description above is the record.