{"id":"CVE-2020-37134","aliases":["EUVD-2020-31034","GHSA-w28g-7hwj-hqwj"],"status":"published","title":"UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service","description":"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.","severity":{"version":"4.0","score":4.6,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00404,"percentile":0.3496,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-770"],"published":"2026-02-05T16:13:36Z","modified":"2026-06-17T03:17:04Z","products":[{"vendor":"ultravnc team","product":"ultravnc viewer"},{"vendor":"uvnc","product":"ultravnc viewer"}],"references":[{"url":"https://www.exploit-db.com/exploits/48291","tags":["exploit"]},{"url":"https://www.uvnc.com/","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/ultravnc-viewer-vncserver-denial-of-service","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-37134"},{"url":"https://www.uvnc.com"},{"url":"https://github.com/advisories/GHSA-w28g-7hwj-hqwj"}],"sources":{"cve":[{"id":"CVE-2020-37134","title":"UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service","description":"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.","status":"published","published":"2026-02-05T16:13:36.934Z","modified":"2026-03-05T01:28:08.821Z","cvss":[{"version":"4.0","score":4.6,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:35:47.22408Z"}],"euvd":[{"id":"EUVD-2020-31034","description":"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.","status":"published","published":"2026-02-05T16:13:36Z","modified":"2026-03-05T01:28:08Z","cvss":[{"version":"4.0","score":4.6,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:48:09.897368Z"}],"ghsa":[{"id":"GHSA-w28g-7hwj-hqwj","title":"UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash...","description":"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.","status":"published","published":"2026-02-05T18:30:31Z","modified":"2026-02-05T18:30:36Z","cvss":[{"version":"4.0","score":4.6,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:06:04.029234Z"}],"nvd":[{"id":"CVE-2020-37134","description":"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.","status":"published","published":"2026-02-05T17:16:08.69Z","modified":"2026-06-17T03:17:04.693Z","cvss":[{"version":"4.0","score":4.6,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:06:48.591569Z"}]}}