CVE-2022-39257

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.

CVSS v3.0 7.5 HIGH

7.5^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients	Vendor Advisory
https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-xcf4	Third Party Advisory
https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19	Release Notes Third Party Advisory
https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c	Patch Third Party Advisory

Advertisement

Configurations

Configuration 1 (hide)

cpe:2.3:a:matrix:software_development_kit:*:*:*:*:*:iphone_os:*:*

Information

Published : 2022-09-28 14:15

Updated : 2022-09-30 09:10

NVD link : CVE-2022-39257

Mitre link : CVE-2022-39257

JSON object : View

CWE

CWE-287

Improper Authentication

Advertisement

Products Affected

matrix

software_development_kit

{"cve": {"data_type": "CVE", "references": {"reference_data": [{"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", "tags": ["Vendor Advisory"], "refsource": "MISC"}, {"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", "tags": ["Third Party Advisory"], "refsource": "CONFIRM"}, {"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", "tags": ["Release Notes", "Third Party Advisory"], "refsource": "MISC"}, {"url": "https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c", "name": "https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262c", "tags": ["Patch", "Third Party Advisory"], "refsource": "MISC"}]}, "data_format": "MITRE", "description": {"description_data": [{"lang": "en", "value": "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."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "en", "value": "CWE-287"}]}]}, "data_version": "4.0", "CVE_data_meta": {"ID": "CVE-2022-39257", "ASSIGNER": "security-advisories@github.com"}}, "impact": {"baseMetricV3": {"cvssV3": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}}, "publishedDate": "2022-09-28T21:15Z", "configurations": {"nodes": [{"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:a:matrix:software_development_kit:*:*:*:*:*:iphone_os:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "0.23.19"}]}], "CVE_data_version": "4.0"}, "lastModifiedDate": "2022-09-30T16:10Z"}