# CVE-2017-12259: Denial of service in Cisco Small Business SPA51x Series IP Phones

> Remote attackers can crash Cisco SPA51x IP phones by sending malformed SIP messages, requiring a manual restart to restore service.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Oct 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-g746-47q2-f2cr

## What is CVE-2017-12259?

CVE-2017-12259 is a high-severity denial of service vulnerability in Cisco Small Business SPA51x Series IP Phones, published on 19 Oct 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the implementation of Session Initiation Protocol (SIP) functionality in Cisco Small Business SPA51x Series IP Phones could allow an unauthenticated, remote attacker to cause an affected device to become unresponsive, resulting in a denial of service (DoS) condition. The vulnerability is due to the improper handling of SIP request messages by an affected device. An attacker could exploit this vulnerability by sending malformed SIP messages to an affected device. A successful exploit could allow the attacker to cause the affected device to become unresponsive, resulting in a DoS condition that persists until the device is restarted manually. This vulnerability affects Cisco Small Business SPA51x Series IP Phones that are running Cisco SPA51x Firmware Release 7.6.2SR1 or earlier. Cisco Bug IDs: CSCvc63982.

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

## Which versions are affected by CVE-2017-12259?

It affects 1 product.


Products: Cisco Small Business Ip Phone Firmware.

## How do I fix CVE-2017-12259?

No fix has been published for CVE-2017-12259 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-12259 being exploited?

There is no known exploitation of CVE-2017-12259 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-12259 and fix it if it is affected.

What it is: CVE-2017-12259 is a high-severity denial of service vulnerability in Cisco Small Business SPA51x Series IP Phones, published on 19 Oct 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-2017-12259 in the wild and no public exploit code.

Affected product: Cisco Small Business SPA51x Series IP Phones. 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-2017-12259/ (Markdown: https://insights.sbomify.com/CVE-2017-12259/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-12259
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-12259
- OSV: https://osv.dev/vulnerability/CVE-2017-12259

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-12259/
Summaries are generated and may contain mistakes; the official description above is the record.