Vulnerability · Published Sep 28, 2022 · Assigned by GitHub_M
CVE-2022-39249Matrix Javascript SDK vulnerable to impersonation via forwarded Megolm sessions
High 7.5
In plain English
A high-severity improper authentication in matrix-js-sdk from matrix-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 70% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | thunderbird | 102.4.0-1.el8_6.alma | ALSA-2022:7190 |
| AlmaLinux:9 | thunderbird | 102.4.0-1.el9_0.alma | ALSA-2022:7178 |
| Alpine:v3.20 | element-web | 1.11.7-r0 | ALPINE-CVE-2022-39249 |
| Alpine:v3.21 | element-web | 1.11.7-r0 | ALPINE-CVE-2022-39249 |
| Alpine:v3.22 | element-web | 1.11.7-r0 | ALPINE-CVE-2022-39249 |
| Alpine:v3.23 | element-web | 1.11.7-r0 | ALPINE-CVE-2022-39249 |
| Alpine:v3.24 | element-web | 1.11.7-r0 | ALPINE-CVE-2022-39249 |
| Rocky Linux:8 | thunderbird | 0:102.4.0-1.el8_6.0.1 | RLSA-2022:7190 |
| Rocky Linux:8 | thunderbird | 0:102.4.0-1.el8_6 | RLSA-2022:7190 |
| Ubuntu:22.04:LTS | node-matrix-js-sdk | no fix listed | UBUNTU-CVE-2022-39249 |
| Ubuntu:24.04:LTS | node-matrix-js-sdk | no fix listed | UBUNTU-CVE-2022-39249 |
| Ubuntu:22.04:LTS | thunderbird | 1:102.4.2+build2-0ubuntu0.22.04.1 | UBUNTU-CVE-2022-39249 |
| Ubuntu:22.04:LTS | thunderbird | 1:102.4.2+build2-0ubuntu0.22.04.1 | USN-5724-1 |
| npm | matrix-js-sdk | 19.7.0 | GHSA-6263-x97c-c4gg |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| matrix-org | matrix-js-sdk | < 19.7.0 |
Weakness: CWE-322, CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76
- https://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0
- https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-6263-x97c-c4gg
- https://github.com/matrix-org/matrix-spec-proposals/pull/3061
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients
- GLSA-202210-35 vendor-advisory