{"schemaVersion":3,"id":"USN-4434-1","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"libvncserver vulnerabilities\n\nRamin Farajpour Cami discovered that LibVNCServer incorrectly handled\ncertain malformed unix socket names. A remote attacker could exploit this\nwith a crafted socket name, leading to a denial of service, or possibly\nexecute arbitrary code. (CVE-2019-20839)\n\nIt was discovered that LibVNCServer did not properly access byte-aligned\ndata. A remote attacker could possibly use this issue to cause\nLibVNCServer to crash, resulting in a denial of service. This issue only\naffected Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. (CVE-2019-20840)\n\nChristian Beier discovered that LibVNCServer incorrectly handled anonymous\nTLS connections. A remote attacker could possibly use this issue to cause\nLibVNCServer to crash, resulting in a denial of service. This issue only\naffected Ubuntu 20.04 LTS. (CVE-2020-14396)\n\nIt was discovered that LibVNCServer incorrectly handled region clipping. A\nremote attacker could possibly use this issue to cause LibVNCServer to\ncrash, resulting in a denial of service. (CVE-2020-14397)\n\nIt was discovered that LibVNCServer did not properly reset incorrectly\nterminated TCP connections. A remote attacker could possibly use this\nissue to cause an infinite loop, resulting in a denial of service.\n(CVE-2020-14398)\n\nIt was discovered that LibVNCServer did not properly access byte-aligned\ndata. A remote attacker could possibly use this issue to cause\nLibVNCServer to crash, resulting in a denial of service. (CVE-2020-14399,\nCVE-2020-14400)\n\nIt was discovered that LibVNCServer incorrectly handled screen scaling on\nthe server side. A remote attacker could use this issue to cause\nLibVNCServer to crash, resulting in a denial of service, or possibly\nexecute arbitrary code. (CVE-2020-14401)\n\nIt was discovered that LibVNCServer incorrectly handled encodings. A\nremote attacker could use this issue to cause LibVNCServer to crash,\nresulting in a denial of service, or possibly execute arbitrary code.\n(CVE-2020-14402, CVE-2020-14403, CVE-2020-14404)\n\nIt was discovered that LibVNCServer incorrectly handled TextChat messages.\nA remote attacker could possibly use this issue to cause LibVNCServer to\ncrash, resulting in a denial of service. (CVE-2020-14405)","dates":{"published":"2020-07-23T20:09:25.000Z","modified":"2026-04-27T15:48:46.367Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":null,"severity":"unknown","version":null,"versionLabel":null,"source":null,"vector":null,"computed":false,"selection":"none"},"metrics":[]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"ubuntu","product":"libvncserver","name":"libvncserver","label":"libvncserver","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/libvncserver","purlType":"deb","versions":[{"text":"< 0.9.10+dfsg-3ubuntu0.16.04.5","noFixRecorded":false,"fixedIn":null},{"text":"< 0.9.11+dfsg-1ubuntu1.3","noFixRecorded":false,"fixedIn":null},{"text":"< 0.9.12+dfsg-9ubuntu0.2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 0.9.10+dfsg-3ubuntu0.16.04.5 | < 0.9.11+dfsg-1ubuntu1.3 | < 0.9.12+dfsg-9ubuntu0.2","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-4434-1","label":"ubuntu.com/security/notices/USN-4434-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2019-20839","label":"ubuntu.com/security/CVE-2019-20839","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2019-20840","label":"ubuntu.com/security/CVE-2019-20840","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14396","label":"ubuntu.com/security/CVE-2020-14396","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14397","label":"ubuntu.com/security/CVE-2020-14397","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14398","label":"ubuntu.com/security/CVE-2020-14398","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14399","label":"ubuntu.com/security/CVE-2020-14399","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14400","label":"ubuntu.com/security/CVE-2020-14400","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14401","label":"ubuntu.com/security/CVE-2020-14401","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14402","label":"ubuntu.com/security/CVE-2020-14402","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14403","label":"ubuntu.com/security/CVE-2020-14403","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14404","label":"ubuntu.com/security/CVE-2020-14404","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2020-14405","label":"ubuntu.com/security/CVE-2020-14405","hostname":"ubuntu.com","tags":["REPORT"]}],"lineage":{"upstream":["CVE-2019-20839","CVE-2019-20840","CVE-2020-14396","CVE-2020-14397","CVE-2020-14398","CVE-2020-14399","CVE-2020-14400","CVE-2020-14401","CVE-2020-14402","CVE-2020-14403","CVE-2020-14404","CVE-2020-14405"],"downstream":[],"duplicates":[],"related":["CVE-2019-20839","CVE-2019-20840","CVE-2020-14396","CVE-2020-14397","CVE-2020-14398","CVE-2020-14399","CVE-2020-14400","CVE-2020-14401","CVE-2020-14402","CVE-2020-14403","CVE-2020-14404","CVE-2020-14405"]},"timeline":[{"kind":"published","date":"2020-07-23T20:09:25.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-04-27T15:48:46.367Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":0,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T16:03:16.846Z","stale":false,"partial":false}}