# CVE-2017-6961: Denial of service in n/a

> Attackers can cause a crash in apng2gif by providing a malicious PNG file that triggers excessive memory allocation.

- **Severity:** Medium 5.5 (`CVSS:3.0/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:** 17 Mar 2017
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-6961, GHSA-hqvw-jgm8-f4v5, UBUNTU-CVE-2017-6961

## What is CVE-2017-6961?

CVE-2017-6961 is a medium-severity denial of service vulnerability in n/a, published on 17 Mar 2017. 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

An issue was discovered in apng2gif 1.7. There is improper sanitization of user input causing huge memory allocations, resulting in a crash. This is related to the read_chunk function using the pChunk->size value (within the PNG file) to determine the amount of memory to allocate.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-6961?

It affects 1 product.


Products: Apng2gif Project Apng2gif.

## How do I fix CVE-2017-6961?

Apply the vendor's patch.

## Is CVE-2017-6961 being exploited?

There is no known exploitation of CVE-2017-6961 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-6960](https://insights.sbomify.com/CVE-2017-6960/): Integer overflow in n/a (high 7.5)
- [CVE-2017-6962](https://insights.sbomify.com/CVE-2017-6962/): Integer overflow in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6961 and fix it if it is affected.

What it is: CVE-2017-6961 is a medium-severity denial of service vulnerability in n/a, published on 17 Mar 2017. 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-2017-6961 in the wild and no public exploit code.

Affected product: n/a. 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-2017-6961/ (Markdown: https://insights.sbomify.com/CVE-2017-6961/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6961
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6961
- OSV: https://osv.dev/vulnerability/CVE-2017-6961

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-6961/
Summaries are generated and may contain mistakes; the official description above is the record.