# CVE-2021-3478: Denial of service in OpenEXR

> An attacker can cause excessive memory consumption and system unavailability by submitting a crafted file to OpenEXR.

- **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:** 31 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-3478, GHSA-fwcc-9735-qjcm, UBUNTU-CVE-2021-3478

## What is CVE-2021-3478?

CVE-2021-3478 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 31 Mar 2021. 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

There's a flaw in OpenEXR's scanline input file functionality in versions before 3.0.0-beta. An attacker able to submit a crafted file to be processed by OpenEXR could consume excessive system memory. The greatest impact of this flaw is to system availability.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2021-3478?

It affects 2 products.


Products: Debian Debian Linux, Openexr Openexr.

## How do I fix CVE-2021-3478?

Upgrade to a fixed version.

## Is CVE-2021-3478 being exploited?

There is no known exploitation of CVE-2021-3478 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3478 and fix it if it is affected.

What it is: CVE-2021-3478 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 31 Mar 2021. 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-2021-3478 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-2021-3478/ (Markdown: https://insights.sbomify.com/CVE-2021-3478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3478
- OSV: https://osv.dev/vulnerability/CVE-2021-3478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3478/
Summaries are generated and may contain mistakes; the official description above is the record.