{"id":"CVE-2022-39246","summary":"matrix-android-sdk2 vulnerable to impersonation via forwarded Megolm sessions","details":"matrix-android-sdk2 is the Matrix SDK for Android. Prior to version 1.5.1, an attacker cooperating with a malicious homeserver can construct messages appearing to have come from another person. Such messages will be marked with a grey shield on some platforms, but this may be missing in others. This attack is possible due to the key forwarding strategy implemented in the matrix-android-sdk2 that is too permissive. Starting with version 1.5.1, the default policy for accepting key forwards has been made more strict in the matrix-android-sdk2. The matrix-android-sdk2 will now only accept forwarded keys in response to previously issued requests and only from own, verified devices. The SDK now sets a `trusted` flag on the decrypted message upon decryption, based on whether the key used to decrypt the message was received from a trusted source. Clients need to ensure that messages decrypted with a key with `trusted = false` are decorated appropriately (for example, by showing a warning for such messages). As a workaroubnd, current users of the SDK can disable key forwarding in their forks using `CryptoService#enableKeyGossiping(enable: Boolean)`.","aliases":["GHSA-2pvj-p485-cp3m"],"modified":"2026-04-10T04:50:19.500548Z","published":"2022-09-28T20:00:19Z","database_specific":{"cwe_ids":["CWE-287","CWE-322"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39246.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.5.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39246.json"},{"type":"ADVISORY","url":"https://github.com/matrix-org/matrix-android-sdk2/security/advisories/GHSA-2pvj-p485-cp3m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-39246"},{"type":"FIX","url":"https://github.com/matrix-org/matrix-android-sdk2/commit/77df720a238d17308deab83ecaa37f7a4740a17e"},{"type":"FIX","url":"https://github.com/matrix-org/matrix-spec-proposals/pull/3061"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/matrix-org/matrix-android-sdk2","events":[{"introduced":"0"},{"fixed":"77df720a238d17308deab83ecaa37f7a4740a17e"}]},{"type":"GIT","repo":"https://github.com/matrix-org/matrix-android-sdk2","events":[{"introduced":"0"},{"fixed":"e1b2844afce399811162b1015c0d4740e6d9de9a"}]},{"type":"GIT","repo":"https://github.com/matrix-org/matrix-android-sdk2","events":[{"introduced":"0"},{"fixed":"77df720a238d17308deab83ecaa37f7a4740a17e"}]},{"type":"GIT","repo":"https://github.com/matrix-org/matrix-android-sdk2","events":[{"introduced":"0"},{"fixed":"e1b2844afce399811162b1015c0d4740e6d9de9a"}]}],"versions":["v0.0.1","v1.0.10","v1.0.11","v1.0.12","v1.0.13","v1.0.16","v1.0.5","v1.0.6","v1.0.7","v1.0.9","v1.1.1","v1.1.4","v1.1.5","v1.1.8","v1.1.9","v1.2.0","v1.2.0-RC1","v1.2.0-RC2","v1.2.0-RC3","v1.2.1","v1.2.2","v1.3.0","v1.3.10","v1.3.13","v1.3.14","v1.3.18","v1.3.2","v1.3.4","v1.3.7","v1.3.8","v1.3.9","v1.4.11","v1.4.13","v1.4.14","v1.4.16","v1.4.2","v1.4.25","v1.4.27","v1.4.32","v1.4.34","v1.4.36"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-39246.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:H/A:N"}]}