# CVE-2009-2051: Denial of service in n/a

> Remote attackers can cause device reload or voice outage via malformed SIP messages in Cisco IOS and Unified Communications Manager.

- **Severity:** High 7.8 (`AV:N/AC:L/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Aug 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-mp73-2m32-64h6

## What is CVE-2009-2051?

CVE-2009-2051 is a high-severity denial of service vulnerability in Cisco Ios, published on 27 Aug 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Cisco IOS 12.2 through 12.4 and 15.0 through 15.1, Cisco IOS XE 2.5.x and 2.6.x before 2.6.1, and Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.x, 5.x before 5.1(3g), 6.x before 6.1(4), and 7.x before 7.1(2) allow remote attackers to cause a denial of service (device reload or voice-services outage) via a malformed SIP INVITE message that triggers an improper call to the sipSafeStrlen function, aka Bug IDs CSCsz40392 and CSCsz43987.

## Which versions are affected by CVE-2009-2051?

It affects 3 products.


Products: Cisco Ios, Cisco Ios Xe, Cisco Unified Communications Manager.

## How do I fix CVE-2009-2051?

No fix has been published for CVE-2009-2051 yet. Limit exposure of the affected software until one is available.

## Is CVE-2009-2051 being exploited?

There is no known exploitation of CVE-2009-2051 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios

- [CVE-2017-12240](https://insights.sbomify.com/CVE-2017-12240/): Cisco IOS and IOS XE Software DHCP Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-3881](https://insights.sbomify.com/CVE-2017-3881/): Cisco IOS and IOS XE Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2018-0167](https://insights.sbomify.com/CVE-2018-0167/): Cisco IOS, XR, and XE Software Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2017-6736](https://insights.sbomify.com/CVE-2017-6736/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-6737](https://insights.sbomify.com/CVE-2017-6737/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2051 and fix it if it is affected.

What it is: CVE-2009-2051 is a high-severity denial of service vulnerability in Cisco Ios, published on 27 Aug 2009. 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-2009-2051 in the wild and no public exploit code.

Affected product: Cisco Ios. 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-2009-2051/ (Markdown: https://insights.sbomify.com/CVE-2009-2051/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2051
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2051
- OSV: https://osv.dev/vulnerability/CVE-2009-2051

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2051/
Summaries are generated and may contain mistakes; the official description above is the record.