CVE-2023-27830 — TightVNC before v2

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-04-12T00:00:00.000Z
• Last modified: 2025-02-08T02:40:24.901Z

09References

• www.tightvnc.com — https://www.tightvnc.com/whatsnew.php
• medium.com — https://medium.com/nestedif/vulnerability-disclosure-privilege-escalation-tightv…
• www.tightvnc.com — https://www.tightvnc.com/news.php