{"id":"CVE-2019-25600","aliases":["EUVD-2019-19942","GHSA-6w7v-w6gw-pm7w"],"status":"published","title":"UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow","description":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00717,"percentile":0.54072,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2026-03-22T13:38:36Z","modified":"2026-06-17T02:32:46Z","products":[{"vendor":"uvnc","product":"ultravnc viewer"}],"references":[{"url":"https://www.exploit-db.com/exploits/46702","tags":["exploit"]},{"url":"https://www.uvnc.com/","tags":["product"]},{"url":"https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/ultravnc-viewer-denial-of-service-via-buffer-overflow","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-25600"},{"url":"https://www.uvnc.com"},{"url":"https://github.com/advisories/GHSA-6w7v-w6gw-pm7w"}],"sources":{"cve":[{"id":"CVE-2019-25600","title":"UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow","description":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.","status":"published","published":"2026-03-22T13:38:36.517Z","modified":"2026-03-24T15:14:43.698Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:20:19.737165Z"}],"euvd":[{"id":"EUVD-2019-19942","description":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.","status":"published","published":"2026-03-22T13:38:36Z","modified":"2026-03-24T15:14:43Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T19:25:29.933437Z"}],"ghsa":[{"id":"GHSA-6w7v-w6gw-pm7w","title":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash...","description":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.","status":"published","published":"2026-03-22T15:31:28Z","modified":"2026-03-22T15:31:34Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/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":"high"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T15:06:47.173687Z"}],"nvd":[{"id":"CVE-2019-25600","description":"UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.","status":"published","published":"2026-03-22T14:16:27.343Z","modified":"2026-06-17T02:32:46.257Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/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":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:05:49.934131Z"}]}}