Auth bypass in Osuosl Twisted Vnc Authentication Proxy

CVE-2022-36436

OSU Open Source Lab VNCAuthProxy through 1.1.1 is affected by an vncap/vnc/protocol.py VNCServerAuthenticator authentication-bypass vulnerability that could allow a malicious actor to gain unauthorized access to a VNC session or to disconnect a legitimate user from a VNC session. A remote attacker with network access to the proxy server could leverage this vulnerability to connect to VNC servers protected by the proxy server without providing any authentication credentials. Exploitation of this issue requires that the proxy server is currently accepting connections for the target VNC server.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (80.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 80.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2022-36436: held from 0.017 to 0.021.

EPSS over last 30 days · oldest: 0.017 · newest: 0.021 · change: +0.003

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2022-36436?
CVE-2022-36436 is a critical-severity vulnerability in Osuosl Twisted Vnc Authentication Proxy, classified under Improper Authentication. CVSS score: 9.8/10. Published 2022-09-14.
How severe is CVE-2022-36436?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2022-36436 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.