Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Matrix | Software Development Kit | < 0.23.19 |
Related Weaknesses (CWE)
References
- https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cbPatchThird Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19Release NotesThird Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-Third Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-maVendor Advisory
- https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cbPatchThird Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19Release NotesThird Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-qxr3-5jmq-Third Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-maVendor Advisory
FAQ
What is CVE-2022-39257?
CVE-2022-39257 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 f...
How severe is CVE-2022-39257?
CVE-2022-39257 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2022-39257?
Check the references section above for vendor advisories and patch information. Affected products include: Matrix Software Development Kit.