{"id":"ALPINE-CVE-2021-40824","details":"A logic error in the room key sharing functionality of Element Android before 1.2.2 and matrix-android-sdk2 (aka Matrix SDK for Android) before 1.2.2 allows a malicious Matrix homeserver present in an encrypted room to steal room encryption keys (via crafted Matrix protocol messages) that were originally sent by affected Matrix clients participating in that room. This allows the attacker to decrypt end-to-end encrypted messages sent by affected clients.","modified":"2026-11-03T06:32:41.355375205Z","published":"2021-09-13T19:15:19.340Z","upstream":["CVE-2021-40824"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-40824"}],"affected":[{"package":{"name":"element-web","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"element-web","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/element-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"riot-web","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/riot-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"riot-web","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/riot-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"riot-web","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/riot-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}},{"package":{"name":"riot-web","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/riot-web?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-40824.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}