# CVE-2009-0758: Denial of service in n/a

> Remote attackers can cause denial of service in Avahi daemon via crafted mDNS packets due to incorrect port byte order handling.

- **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:** Yes
- **Published:** 3 Mar 2009
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-0758, GHSA-g7f8-4qm9-qgg5

## What is CVE-2009-0758?

CVE-2009-0758 is a high-severity denial of service vulnerability in n/a, published on 3 Mar 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The originates_from_local_legacy_unicast_socket function in avahi-core/server.c in avahi-daemon 0.6.23 does not account for the network byte order of a port number when processing incoming multicast packets, which allows remote attackers to cause a denial of service (network bandwidth and CPU consumption) via a crafted legacy unicast mDNS query packet that triggers a multicast packet storm.

Weakness: CWE-399

## Which versions are affected by CVE-2009-0758?

It affects 1 product.


Products: Avahi Avahi-Daemon.

## How do I fix CVE-2009-0758?

Upgrade to a fixed version.

## Is CVE-2009-0758 being exploited?

There is no known exploitation of CVE-2009-0758 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-0758 and fix it if it is affected.

What it is: CVE-2009-0758 is a high-severity denial of service vulnerability in n/a, published on 3 Mar 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-2009-0758 in the wild and no public exploit code.

Affected product: n/a. 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-2009-0758/ (Markdown: https://insights.sbomify.com/CVE-2009-0758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-0758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-0758
- OSV: https://osv.dev/vulnerability/CVE-2009-0758

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From sbomify Insights: https://insights.sbomify.com/CVE-2009-0758/
Summaries are generated and may contain mistakes; the official description above is the record.