{"id":"UBUNTU-CVE-2021-3782","details":"An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wl_shm buffer objects, or if it can coerce the server to create a large number of external references to the buffer storage. With the reference count overflowing, a use-after-free can be constructed on the wl_shm_pool tracking structure, where values may be incremented or decremented; it may also be possible to construct a limited oracle to leak 4 bytes of server-side memory to the attacking client at a time.","modified":"2026-04-22T12:58:48.478322Z","published":"2022-08-30T20:51:00Z","related":["USN-5614-1","USN-5614-2"],"upstream":["CVE-2021-3782"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3782"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2021-3782"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5614-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5614-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3782"}],"affected":[{"package":{"name":"wayland","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/wayland@1.12.0-1~ubuntu16.04.3+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.12.0-1~ubuntu16.04.3+esm1"}]}],"versions":["1.8.1-1","1.9.0-1","1.12.0-1~ubuntu16.04.1","1.12.0-1~ubuntu16.04.2","1.12.0-1~ubuntu16.04.3"],"ecosystem_specific":{"binaries":[{"binary_version":"1.12.0-1~ubuntu16.04.3+esm1","binary_name":"libwayland-bin"},{"binary_name":"libwayland-client0","binary_version":"1.12.0-1~ubuntu16.04.3+esm1"},{"binary_name":"libwayland-cursor0","binary_version":"1.12.0-1~ubuntu16.04.3+esm1"},{"binary_name":"libwayland-server0","binary_version":"1.12.0-1~ubuntu16.04.3+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3782.json"}},{"package":{"name":"wayland","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/wayland@1.16.0-1ubuntu1.1~18.04.4?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.16.0-1ubuntu1.1~18.04.4"}]}],"versions":["1.14.0-1","1.14.0-2","1.16.0-1ubuntu1.1~18.04.1","1.16.0-1ubuntu1.1~18.04.3"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libwayland-bin","binary_version":"1.16.0-1ubuntu1.1~18.04.4"},{"binary_name":"libwayland-client0","binary_version":"1.16.0-1ubuntu1.1~18.04.4"},{"binary_name":"libwayland-cursor0","binary_version":"1.16.0-1ubuntu1.1~18.04.4"},{"binary_name":"libwayland-egl1","binary_version":"1.16.0-1ubuntu1.1~18.04.4"},{"binary_name":"libwayland-server0","binary_version":"1.16.0-1ubuntu1.1~18.04.4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3782.json"}},{"package":{"name":"wayland","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/wayland@1.18.0-1ubuntu0.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.18.0-1ubuntu0.1"}]}],"versions":["1.17.0-1","1.17.0-1build1","1.17.0-1build2","1.18.0-1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libwayland-bin","binary_version":"1.18.0-1ubuntu0.1"},{"binary_name":"libwayland-client0","binary_version":"1.18.0-1ubuntu0.1"},{"binary_name":"libwayland-cursor0","binary_version":"1.18.0-1ubuntu0.1"},{"binary_name":"libwayland-egl1","binary_version":"1.18.0-1ubuntu0.1"},{"binary_name":"libwayland-server0","binary_version":"1.18.0-1ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3782.json"}},{"package":{"name":"wayland","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/wayland@1.20.0-1ubuntu0.1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.0-1ubuntu0.1"}]}],"versions":["1.19.0-2build1","1.20.0-1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libwayland-bin","binary_version":"1.20.0-1ubuntu0.1"},{"binary_name":"libwayland-client0","binary_version":"1.20.0-1ubuntu0.1"},{"binary_name":"libwayland-cursor0","binary_version":"1.20.0-1ubuntu0.1"},{"binary_version":"1.20.0-1ubuntu0.1","binary_name":"libwayland-egl1"},{"binary_name":"libwayland-server0","binary_version":"1.20.0-1ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3782.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H"},{"type":"Ubuntu","score":"medium"}]}