# CVE-2021-27815: Null dereference in n/a

> Attackers can cause a denial of service by uploading a malicious JPEG file to the exif command line tool, crashing the application.

- **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:** 14 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-27815, GHSA-f35c-rqpm-6c5v, MGASA-2021-0252, UBUNTU-CVE-2021-27815

## What is CVE-2021-27815?

CVE-2021-27815 is a medium-severity vulnerability in Fedoraproject Fedora, published on 14 Apr 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

NULL Pointer Deference in the exif command line tool, when printing out XML formatted EXIF data, in exif v0.6.22 and earlier allows attackers to cause a Denial of Service (DoS) by uploading a malicious JPEG file, causing the application to crash.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-27815?

It affects 2 products.


Products: Fedoraproject Fedora, Libexif Project Exif.

## How do I fix CVE-2021-27815?

Upgrade to a fixed version.

## Is CVE-2021-27815 being exploited?

There is no known exploitation of CVE-2021-27815 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27815 and fix it if it is affected.

What it is: CVE-2021-27815 is a medium-severity vulnerability in Fedoraproject Fedora, published on 14 Apr 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-2021-27815 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-27815/ (Markdown: https://insights.sbomify.com/CVE-2021-27815/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27815
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27815
- OSV: https://osv.dev/vulnerability/CVE-2021-27815

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27815/
Summaries are generated and may contain mistakes; the official description above is the record.