# CVE-2023-45675: 0 byte write heap buffer overflow in start_decoder in stb_vorbis

> A crafted Ogg Vorbis file triggers a heap buffer overflow in stb_vorbis, potentially allowing attackers to execute arbitrary code.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Oct 2023
- **Updated:** 13 Feb 2025
- **Also known as:** DEBIAN-CVE-2023-45675, OESA-2024-1410, OESA-2024-1411, UBUNTU-CVE-2023-45675

## What is CVE-2023-45675?

CVE-2023-45675 is a medium-severity memory corruption vulnerability in nothings stb, published on 20 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

stb_vorbis is a single file MIT licensed library for processing ogg vorbis files. A crafted file may trigger out of bounds write in `f->vendor[len] = (char)'\0';`. The root cause is that if the len read in `start_decoder` is `-1` and `len + 1` becomes 0 when passed to `setup_malloc`. The `setup_malloc` behaves differently when `f->alloc.alloc_buffer` is pre-allocated. Instead of returning `NULL` as in `malloc` case it shifts the pre-allocated buffer by zero and returns the currently available memory block. This issue may lead to code execution.

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

## Which versions are affected by CVE-2023-45675?

It affects 1 product.


Products: Nothings Stb Vorbis.c.

## How do I fix CVE-2023-45675?

Apply the vendor's patch.

## Is CVE-2023-45675 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-45675 exists.

## Other vulnerabilities in nothings stb

- [CVE-2023-45676](https://insights.sbomify.com/CVE-2023-45676/): Multi-byte write heap buffer overflow in start_decoder in stb_vorbis (high 7.3)
- [CVE-2023-45677](https://insights.sbomify.com/CVE-2023-45677/): Heap buffer out of bounds write in start_decoder in stb_vorbis (high 7.3)
- [CVE-2023-45679](https://insights.sbomify.com/CVE-2023-45679/): Attempt to free an uninitialized memory pointer in vorbis_deinit in stb_vorbis (high 7.3)
- [CVE-2023-45681](https://insights.sbomify.com/CVE-2023-45681/): Out of bounds heap buffer write in stb_vorbis (high 7.3)
- [CVE-2023-45678](https://insights.sbomify.com/CVE-2023-45678/): Off-by-one heap buffer write in start_decoder in stb_vorbis (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-45675 and fix it if it is affected.

What it is: CVE-2023-45675 is a medium-severity memory corruption vulnerability in nothings stb, published on 20 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-45675 exists.

Affected product: nothings stb. 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-2023-45675/ (Markdown: https://insights.sbomify.com/CVE-2023-45675/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-45675
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-45675
- OSV: https://osv.dev/vulnerability/CVE-2023-45675

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-45675/
Summaries are generated and may contain mistakes; the official description above is the record.