# CVE-2018-20846: Denial of service in n/a

> Remote attackers can cause a denial of service via out-of-bounds accesses in OpenJPEG, affecting applications using the library.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 26 Jun 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-20846, ECHO-85f8-13d6-6594, GHSA-g752-v9rv-66cg, UBUNTU-CVE-2018-20846

## What is CVE-2018-20846?

CVE-2018-20846 is a medium-severity denial of service vulnerability in Uclouvain Openjpeg, published on 26 Jun 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Out-of-bounds accesses in the functions pi_next_lrcp, pi_next_rlcp, pi_next_rpcl, pi_next_pcrl, pi_next_rpcl, and pi_next_cprl in openmj2/pi.c in OpenJPEG through 2.3.0 allow remote attackers to cause a denial of service (application crash).

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-20846?

It affects 1 product.


Products: Uclouvain Openjpeg.

## How do I fix CVE-2018-20846?

Upgrade to a fixed version.

## Is CVE-2018-20846 being exploited?

There is no known exploitation of CVE-2018-20846 in the wild and no public exploit code.

## Other vulnerabilities in Uclouvain Openjpeg

- [CVE-2013-4289](https://insights.sbomify.com/CVE-2013-4289/): Integer overflow in n/a (critical 10.0)
- [CVE-2013-4290](https://insights.sbomify.com/CVE-2013-4290/): Memory corruption in n/a (critical 10.0)
- [CVE-2012-3358](https://insights.sbomify.com/CVE-2012-3358/): Memory corruption in n/a (critical 10.0)
- [CVE-2018-7648](https://insights.sbomify.com/CVE-2018-7648/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-17479](https://insights.sbomify.com/CVE-2017-17479/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20846 and fix it if it is affected.

What it is: CVE-2018-20846 is a medium-severity denial of service vulnerability in Uclouvain Openjpeg, published on 26 Jun 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-20846 in the wild and no public exploit code.

Affected product: Uclouvain Openjpeg. 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-2018-20846/ (Markdown: https://insights.sbomify.com/CVE-2018-20846/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20846
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20846
- OSV: https://osv.dev/vulnerability/CVE-2018-20846

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-20846/
Summaries are generated and may contain mistakes; the official description above is the record.