# CVE-2018-20199: Null dereference in n/a

> A NULL pointer dereference in FAAD2 allows attackers to cause a denial of service via crafted audio files.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-20199, CLEANSTART-2023-DO62878, DEBIAN-CVE-2018-20199, GHSA-8fmv-4jcp-rv3m, UBUNTU-CVE-2018-20199

## What is CVE-2018-20199?

CVE-2018-20199 is a medium-severity vulnerability in Debian Debian Linux, published on 18 Dec 2018. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A NULL pointer dereference was discovered in ifilter_bank of libfaad/filtbank.c in Freeware Advanced Audio Decoder 2 (FAAD2) 2.8.8. The vulnerability causes a segmentation fault and application crash, which leads to denial of service because adding to windowed output is mishandled in the ONLY_LONG_SEQUENCE case.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2018-20199?

It affects 2 products.


Products: Audiocoding Freeware Advanced Audio Decoder 2, Debian Debian Linux.

## How do I fix CVE-2018-20199?

Apply the vendor's patch.

## Is CVE-2018-20199 being exploited?

There is no known exploitation of CVE-2018-20199 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2019-15296](https://insights.sbomify.com/CVE-2019-15296/): Memory corruption in n/a (high 7.8)
- [CVE-2018-20194](https://insights.sbomify.com/CVE-2018-20194/): Memory corruption in n/a (high 7.8)
- [CVE-2018-20196](https://insights.sbomify.com/CVE-2018-20196/): Memory corruption in n/a (high 7.8)
- [CVE-2018-20197](https://insights.sbomify.com/CVE-2018-20197/): Memory corruption in n/a (high 7.8)
- [CVE-2018-19502](https://insights.sbomify.com/CVE-2018-19502/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20199 and fix it if it is affected.

What it is: CVE-2018-20199 is a medium-severity vulnerability in Debian Debian Linux, published on 18 Dec 2018. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-20199 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2018-20199/ (Markdown: https://insights.sbomify.com/CVE-2018-20199/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20199
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20199
- OSV: https://osv.dev/vulnerability/CVE-2018-20199

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20199/
Summaries are generated and may contain mistakes; the official description above is the record.