Vulnerability Description
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)`.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Matrix | Software Development Kit | < 1.5.1 |
Related Weaknesses (CWE)
References
- https://github.com/matrix-org/matrix-android-sdk2/commit/77df720a238d17308deab83PatchThird Party Advisory
- https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.5.1Release NotesThird Party Advisory
- https://github.com/matrix-org/matrix-android-sdk2/security/advisories/GHSA-2pvj-MitigationPatchThird Party Advisory
- https://github.com/matrix-org/matrix-spec-proposals/pull/3061PatchThird Party Advisory
- https://github.com/matrix-org/matrix-android-sdk2/commit/77df720a238d17308deab83PatchThird Party Advisory
- https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.5.1Release NotesThird Party Advisory
- https://github.com/matrix-org/matrix-android-sdk2/security/advisories/GHSA-2pvj-MitigationPatchThird Party Advisory
- https://github.com/matrix-org/matrix-spec-proposals/pull/3061PatchThird Party Advisory
FAQ
What is CVE-2022-39246?
CVE-2022-39246 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 m...
How severe is CVE-2022-39246?
CVE-2022-39246 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-2022-39246?
Check the references section above for vendor advisories and patch information. Affected products include: Matrix Software Development Kit.