CVE-2025-27458
CWE-327Published: July 3, 2025· Updated: Jun 17, 2026
Official Description
The VNC authentication mechanism bases on a challenge-response system where both server and client use the same password for encryption. The challenge is sent from the server to the client, is encrypted by the client and sent back. The server does the same encryption locally and if the responses match it is prooven that the client knows the correct password. Since all VNC communication is unencrypted, an attacker can obtain the challenge and response and try to derive the password from this information.
Technical Analysis
CVE-2025-27458 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (9)
Quick Facts
Related CVEs (CWE-327)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-27458 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts