# CVE-2025-64503: [BIGSLEEP-434615384] cups-filters 1.x: out of bounds write in pdftoraster

> Crafted PDFs trigger an integer overflow in pdftoraster, causing an out-of-bounds write that may allow code execution or crashes.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Nov 2025
- **Updated:** 13 Nov 2025
- **Also known as:** DEBIAN-CVE-2025-64503, GHSA-893j-2wr2-wrh9, UBUNTU-CVE-2025-64503

## What is CVE-2025-64503?

CVE-2025-64503 is a medium-severity vulnerability in OpenPrinting cups-filters, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. In cups-filters prior to 1.28.18, by crafting a PDF file with a large `MediaBox` value, an attacker can cause CUPS-Filter 1.x’s `pdftoraster` tool to write beyond the bounds of an array. First, a PDF with a large `MediaBox` width value causes `header.cupsWidth` to become large.  Next, the calculation of `bytesPerLine = (header.cupsBitsPerPixel * header.cupsWidth + 7) / 8` overflows, resulting in a small value. Then, `lineBuf` is allocated with the small `bytesPerLine` size. Finally, `convertLineChunked` calls `writePixel8`, which attempts to write to `lineBuf` outside of its buffer size (out of bounds write). In libcupsfilters, the maintainers found the same `bytesPerLine` multiplication without overflow check, but the provided test case does not cause an overflow there, because the values are different. Commit 50d94ca0f2fa6177613c97c59791bde568631865 contains a patch, which is incorporated into cups-filters version 1.28.18.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-64503?

It affects 2 products.


Products: Openprinting Cups-Filters, Openprinting Libcupsfilters.

## How do I fix CVE-2025-64503?

Upgrade to a fixed version.

## Is CVE-2025-64503 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-64503 exists.

## Other vulnerabilities in OpenPrinting cups-filters

- [CVE-2025-57812](https://insights.sbomify.com/CVE-2025-57812/): [BIGSLEEP-434612419] CUPS-Filters has heap-buffer-overflow write in `cfImageLut()` (low 3.7)
- [CVE-2025-64524](https://insights.sbomify.com/CVE-2025-64524/): CUPS rastertopclx Filter Vulnerable to Heap Buffer Overflow Leading to Potential Arbitrary Code Execution (low 3.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-64503 and fix it if it is affected.

What it is: CVE-2025-64503 is a medium-severity vulnerability in OpenPrinting cups-filters, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-64503 exists.

Affected product: OpenPrinting cups-filters. 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-2025-64503/ (Markdown: https://insights.sbomify.com/CVE-2025-64503/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-64503
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-64503
- OSV: https://osv.dev/vulnerability/CVE-2025-64503

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-64503/
Summaries are generated and may contain mistakes; the official description above is the record.