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Vulnerability record · CVE-2006-2206 · published 5 May 2006

CVE-2006-2206: Ultravnc vulnerability

Ultravnc · Ultravnc

The MS-Logon authentication scheme in UltraVNC (aka Ultr@VNC) 1.0.1 uses weak encryption (XOR) for challenge/response, which allows remote attackers to gain privileges by sniffing and decrypting passwords.

10.0 CVSS 2.0 High EPSS 2.1% · top 18.7%
10.0CVSS 2.0 base score
2.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
16 Jun 2026Last modified by NVD

Description

The MS-Logon authentication scheme in UltraVNC (aka Ultr@VNC) 1.0.1 uses weak encryption (XOR) for challenge/response, which allows remote attackers to gain privileges by sniffing and decrypting passwords.

AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://archives.neohapsis.com/archives/bugtraq/2006-05/0057.html
http://www.securityfocus.com/bid/17824 Exploit
https://exchange.xforce.ibmcloud.com/vulnerabilities/26283
http://archives.neohapsis.com/archives/bugtraq/2006-05/0057.html
http://www.securityfocus.com/bid/17824 Exploit
https://exchange.xforce.ibmcloud.com/vulnerabilities/26283

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2009-0388Tightvnc vulnerabilityMultiple integer signedness errors in (1) UltraVNC 1.0.2 and 1.0.5 and (2) TightVnc 1.3.9 allow remote VNC servers to cause a denial of service (heap…EPSS 13%9.3CVE-2008-5001Ultravnc memory buffer overflow vulnerabilityMultiple stack-based buffer overflows in multiple functions in vncviewer/FileTransfer.cpp in vncviewer for UltraVNC 1.0.2 and 1.0.4 before 01252008, …EPSS 5.6%9.3CVE-2008-0610Ultravnc memory buffer overflow vulnerabilityStack-based buffer overflow in the ClientConnection::NegotiateProtocolVersion function in vncviewer/ClientConnection.cpp in vncviewer for UltraVNC 1.…EPSS 39%6.9CVE-2010-5248Ultravnc vulnerabilityUntrusted search path vulnerability in UltraVNC 1.0.8.2 allows local users to gain privileges via a Trojan horse vnclang.dll file in the current work…EPSS 0.40%

Source: NIST National Vulnerability Database (record CVE-2006-2206), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.