{"api_version":"1","generated_at":"2026-07-23T13:34:19+00:00","cve":"CVE-2022-39257","urls":{"html":"https://cve.report/CVE-2022-39257","api":"https://cve.report/api/cve/CVE-2022-39257.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2022-39257","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2022-39257"},"summary":{"title":"CVE-2022-39257","description":"Matrix iOS SDK allows developers to build iOS apps compatible with Matrix. Prior to version 0.23.19, 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 matrix-ios-sdk implementing a too permissive key forwarding strategy. The default policy for accepting key forwards has been made more strict in the matrix-ios-sdk version 0.23.19. matrix-ios-sdk 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). This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2022-09-28 21:15:00","updated_at":"2022-09-30 16:10:00"},"problem_types":["CWE-287"],"metrics":[],"references":[{"url":"https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients","name":"https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients","refsource":"MISC","tags":[],"title":"Upgrade now to address E2EE vulnerabilities in matrix-js-sdk, matrix-ios-sdk and matrix-android-sdk2 | Matrix.org","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c","name":"https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c","refsource":"MISC","tags":[],"title":"Resolve multiple CVEs · matrix-org/matrix-ios-sdk@5ca86c3 · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-xcf4","name":"https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-xcf4","refsource":"CONFIRM","tags":[],"title":"Impersonation via forwarded Megolm sessions · Advisory · matrix-org/matrix-ios-sdk · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19","name":"https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19","refsource":"MISC","tags":[],"title":"Release v0.23.19 · matrix-org/matrix-ios-sdk · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2022-39257","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-39257","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2022","cve_id":"39257","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"matrix","cpe5":"software_development_kit","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"iphone_os","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2022-39257","STATE":"PUBLIC","TITLE":"Matrix iOS SDK vulnerable to impersonation via forwarded Megolm sessions"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"matrix-ios-sdk","version":{"version_data":[{"version_value":"< 0.23.19"}]}}]},"vendor_name":"matrix-org"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Matrix iOS SDK allows developers to build iOS apps compatible with Matrix. 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This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-322: Key Exchange without Entity Authentication"}]},{"description":[{"lang":"eng","value":"CWE-287: Improper Authentication"}]}]},"references":{"reference_data":[{"name":"https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients","refsource":"MISC","url":"https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients"},{"name":"https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c","refsource":"MISC","url":"https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c"},{"name":"https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19","refsource":"MISC","url":"https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19"},{"name":"https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-xcf4","refsource":"CONFIRM","url":"https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-xcf4"}]},"source":{"advisory":"GHSA-qxr3-5jmq-xcf4","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2022-09-28 21:15:00","lastModifiedDate":"2022-09-30 16:10:00","problem_types":["CWE-287"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:matrix:software_development_kit:*:*:*:*:*:iphone_os:*:*","versionEndExcluding":"0.23.19","cpe_name":[]}]}]}},"legacy_mitre":{"record":null,"notes":[]}}}