{"id":"CVE-2019-20840","details":"An issue was discovered in LibVNCServer before 0.9.13. libvncserver/ws_decode.c can lead to a crash because of unaligned accesses in hybiReadAndDecode.","modified":"2026-04-11T09:39:56.271752Z","published":"2020-06-17T16:15:11.523Z","related":["SUSE-SU-2020:1922-1","SUSE-SU-2020:2167-1","openSUSE-SU-2020:0988-1","openSUSE-SU-2020:1025-1","openSUSE-SU-2020:1056-1","openSUSE-SU-2024:10598-1"],"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/"},{"type":"ADVISORY","url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html"},{"type":"ADVISORY","url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html"},{"type":"ADVISORY","url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html"},{"type":"ADVISORY","url":"https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13"},{"type":"ADVISORY","url":"https://usn.ubuntu.com/4434-1/"},{"type":"FIX","url":"https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf"},{"type":"FIX","url":"https://github.com/LibVNC/libvncserver/commit/0cf1400c61850065de590d403f6d49e32882fd76"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/libvnc/libvncserver","events":[{"introduced":"0"},{"last_affected":"0a70095271d845d16a3ed17354841b01f33963ad"},{"fixed":"0cf1400c61850065de590d403f6d49e32882fd76"}],"database_specific":{"versions":[{"introduced":"0"},{"last_affected":"0.9.12"}]}}],"versions":["LibVNCServer-0.9.10","LibVNCServer-0.9.11","LibVNCServer-0.9.12","LibVNCServer-0.9.8","LibVNCServer-0.9.9","X11VNC_0_9_10","X11VNC_0_9_11","X11VNC_0_9_12","X11VNC_0_9_7","X11VNC_0_9_8","X11VNC_0_9_9","X11VNC_REL_0_9_4","X11VNC_REL_0_9_5","X11VNC_REL_0_9_6"],"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"14.04"}]},{"events":[{"introduced":"0"},{"last_affected":"16.04"}]},{"events":[{"introduced":"0"},{"last_affected":"16.04"}]},{"events":[{"introduced":"0"},{"last_affected":"18.04"}]},{"events":[{"introduced":"0"},{"last_affected":"18.10"}]},{"events":[{"introduced":"0"},{"last_affected":"20.04"}]},{"events":[{"introduced":"0"},{"last_affected":"8.0"}]},{"events":[{"introduced":"0"},{"last_affected":"9.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"3.0.0.0"},{"fixed":"3.2.1.0"}]},{"events":[{"introduced":"0"},{"last_affected":"15.2"}]}],"vanir_signatures_modified":"2026-04-11T09:39:56Z","vanir_signatures":[{"deprecated":false,"target":{"function":"hybiReadAndDecode","file":"libvncserver/ws_decode.c"},"signature_type":"Function","id":"CVE-2019-20840-10709c66","signature_version":"v1","source":"https://github.com/libvnc/libvncserver/commit/0cf1400c61850065de590d403f6d49e32882fd76","digest":{"length":4063,"function_hash":"180079713415210745791807162750284308920"}},{"deprecated":false,"target":{"file":"libvncserver/ws_decode.c"},"signature_type":"Line","id":"CVE-2019-20840-337dc46d","signature_version":"v1","source":"https://github.com/libvnc/libvncserver/commit/0cf1400c61850065de590d403f6d49e32882fd76","digest":{"threshold":0.9,"line_hashes":["280535027786460026972189112772063445853","50701751959996758734036103654922009095","152558449667183412663568482169208692828","327930894662464802945272025504953063997","187881109947118880620593900587007315645","215302365506936472057092840460876039458","50659555013314031717534322792322098385","184898503279201702730802996537756075167","96434419174010811701165366566747251317","176232627971923197157543118542926500038"]}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-20840.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}