CVE-2022-39249
Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages appearing to have come from another person.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.06%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, 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-js-sdk implementing a too permissive key forwarding strategy on the receiving end. Starting with version 19.7.0, the default policy for accepting key forwards has been made more strict in the matrix-js-sdk. matrix-js-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 homeserver and an attacker, and those who trust your homeservers do not need a workaround.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 1.06% probability · 63th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287, CWE-322
- Affected
- matrix/javascript sdk
- Source
- security-advisories@github.com
References
- https://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76Patch, Third Party Advisory
- https://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0Release Notes, Third Party Advisory
- https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-6263-x97c-c4ggThird Party Advisory
- https://github.com/matrix-org/matrix-spec-proposals/pull/3061Patch, Third Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clientsVendor Advisory
- https://security.gentoo.org/glsa/202210-35Third Party Advisory
- https://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76Patch, Third Party Advisory
- https://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0Release Notes, Third Party Advisory
- https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-6263-x97c-c4ggThird Party Advisory
- https://github.com/matrix-org/matrix-spec-proposals/pull/3061Patch, Third Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clientsVendor Advisory
- https://security.gentoo.org/glsa/202210-35Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.