# CVE-2018-7421: Denial of service in n/a

> An attacker can cause Wireshark to enter an infinite loop via a malicious DMP packet, leading to application denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/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:** Yes
- **Published:** 23 Feb 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-7421, GHSA-7mvc-3rvp-5f4m, UBUNTU-CVE-2018-7421

## What is CVE-2018-7421?

CVE-2018-7421 is a high-severity denial of service vulnerability in Wireshark Wireshark, published on 23 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Wireshark 2.2.0 to 2.2.12 and 2.4.0 to 2.4.4, the DMP dissector could go into an infinite loop. This was addressed in epan/dissectors/packet-dmp.c by correctly supporting a bounded number of Security Categories for a DMP Security Classification.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2018-7421?

It affects 1 product.


Products: Wireshark Wireshark.

## How do I fix CVE-2018-7421?

Upgrade to a fixed version.

## Is CVE-2018-7421 being exploited?

There is no known exploitation of CVE-2018-7421 in the wild and no public exploit code.

## Other vulnerabilities in Wireshark Wireshark

- [CVE-2011-0444](https://insights.sbomify.com/CVE-2011-0444/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-2994](https://insights.sbomify.com/CVE-2010-2994/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-2995](https://insights.sbomify.com/CVE-2010-2995/): Memory corruption in n/a (critical 10.0)
- [CVE-2009-1266](https://insights.sbomify.com/CVE-2009-1266/): Other in n/a (critical 10.0)
- [CVE-2009-1210](https://insights.sbomify.com/CVE-2009-1210/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-7421 and fix it if it is affected.

What it is: CVE-2018-7421 is a high-severity denial of service vulnerability in Wireshark Wireshark, published on 23 Feb 2018. 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-2018-7421 in the wild and no public exploit code.

Affected product: Wireshark Wireshark. 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-2018-7421/ (Markdown: https://insights.sbomify.com/CVE-2018-7421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-7421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-7421
- OSV: https://osv.dev/vulnerability/CVE-2018-7421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-7421/
Summaries are generated and may contain mistakes; the official description above is the record.