CVE Feed

    Dashboard / CVE / CVE-2020-37134

    CVE-2020-37134

    UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash.

    Published:Feb 5, 2026
    Last Modified:Apr 15, 2026
    EPS:Feb 5, 2026
    EPSS Score:0.00014
    CVSS Score:7.5

    Affected Products

    Vendor
    Ultravnc
    Product
    Ultravnc
    Vendor
    Ultravnc
    Product
    Vnc Viewer

    Exploits

    No exploit reference

    Related CVEs

    CVE-2026-4962 (CVSS 6.4) — A security flaw has been discovered in UltraVNC up to 1.6.4.0. Affected by this issue is some unknown function…
    CVE-2026-3787 (CVSS 6.4) — A weakness has been identified in UltraVNC 1.6.4.0 on Windows. This affects an unknown function in the library…
    CVE-2020-37133 (CVSS 6.7) — UltraVNC Launcher 1.2.4.0 contains a denial of service vulnerability in the Repeater Host configuration field …
    CVE-2020-37132 (CVSS 6.7) — UltraVNC Launcher 1.2.4.0 contains a denial of service vulnerability in its password configuration properties …
    CVE-2010-5248 (CVSS 6.9) — Untrusted search path vulnerability in UltraVNC 1.0.8.2 allows local users to gain privileges via a Trojan hor…
    CVE-2009-0388 (CVSS 10) — Multiple integer signedness errors in (1) UltraVNC 1.0.2 and 1.0.5 and (2) TightVnc 1.3.9 allow remote VNC ser…
    CVE-2008-5001 (CVSS 9.3) — Multiple stack-based buffer overflows in multiple functions in vncviewer/FileTransfer.cpp in vncviewer for Ult…
    CVE-2008-0610 (CVSS 9.3) — Stack-based buffer overflow in the ClientConnection::NegotiateProtocolVersion function in vncviewer/ClientConn…
    CVE-2006-2206 (CVSS 10) — The MS-Logon authentication scheme in UltraVNC (aka Ultr@VNC) 1.0.1 uses weak encryption (XOR) for challenge/r…

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High