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Fencer Vulns
high 7.5

CVE-2022-39249 json

Matrix Javascript SDK vulnerable to impersonation via forwarded Megolm sessions

published 2022-09-28 4 y ago modified 2026-06-17 4 mo ago also GHSA-6263-x97c-c4gg , EUVD-2022-6714

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm matrix-js-sdk 19.7.0
  • matrix javascript_sdk 19.7.0
  • thunderbird Ubuntu 18.04 LTS 1:102.4.2+build2-0ubuntu0.18.04.1
  • thunderbird Ubuntu 20.04 LTS 1:102.4.2+build2-0ubuntu0.20.04.1
  • thunderbird Ubuntu 22.04 LTS 1:102.4.2+build2-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2022-39249

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 9 102.4.0-1.el9_0
  • thunderbird RHEL 7 102.4.0-1.el7_9
  • thunderbird RHEL 8 102.4.0-1.el8_6
  • thunderbird RHEL 8.4 EUS 102.4.0-1.el8_4
  • thunderbird RHEL 8.1 E4S 102.4.0-1.el8_1
  • thunderbird RHEL 8.2 EUS 102.4.0-1.el8_2

red hat advisories RHSA-2022:7178RHSA-2022:7181RHSA-2022:7184RHSA-2022:7183RHSA-2022:7190RHSA-2022:7182

  • MozillaThunderbird SLE Workstation Extension 15 SP4, SLE Workstation Extension 15 SP3, SLE Module for Package Hub 15 SP4 +3 more 102.4.0-150200.8.85.1

suse advisories SUSE-SU-2022:3800-1

  • element-desktop openSUSE Tumbleweed 1.11.8-1.1
  • element-web openSUSE Tumbleweed 1.11.8-1.1
  • MozillaThunderbird openSUSE Tumbleweed 102.3.1-1.1

opensuse advisories openSUSE-SU-2024:12374-1openSUSE-SU-2024:12375-1openSUSE-SU-2024:12379-1

  • thunderbird AlmaLinux 9 102.4.0-1.el9_0.alma
  • thunderbird AlmaLinux 8 102.4.0-1.el8_6.alma

almalinux advisories ALSA-2022:7178ALSA-2022:7190

  • thunderbird Rocky Linux 8 102.4.0-1.el8_6
  • thunderbird Rocky Linux 8 102.4.0-1.el8_6.0.1

rocky linux advisories RLSA-2022:7190

  • riot-web Alpine 3.17, Alpine 3.16 1.11.7-r0
  • element-web Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 1.11.7-r0

alpine advisories ALPINE-CVE-2022-39249

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-39249 updated cvss 7.5

Mozilla: Matrix SDK bundled with Thunderbird vulnerable to an impersonation attack by malicious server administrators

  • Red Hat Enterprise Linux 6 thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) thunderbird 102.4.0-1.el8_6
    fixed: vendor fix RHSA-2022:7190
  • Red Hat Enterprise Linux AppStream (v. 9) thunderbird 102.4.0-1.el9_0
    fixed: vendor fix RHSA-2022:7178
  • Red Hat Enterprise Linux AppStream E4S (v. 8.1) thunderbird 102.4.0-1.el8_1
    fixed: vendor fix RHSA-2022:7183
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) thunderbird 102.4.0-1.el8_2
    fixed: vendor fix RHSA-2022:7182
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) thunderbird 102.4.0-1.el8_4
    fixed: vendor fix RHSA-2022:7181
  • Red Hat Enterprise Linux Client (v. 7) thunderbird 102.4.0-1.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) thunderbird 102.4.0-1.el7_9 Red Hat Enterprise Linux Workstation (v. 7) thunderbird 102.4.0-1.el7_9
    fixed: vendor fix RHSA-2022:7184

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

1.28% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
npm matrix-js-sdk
<19.7.0
19.7.0

Affected products

  • matrix-org matrix-js-sdk

Classification

Weakness
  • CWE-322 Key Exchange without Entity Authentication
  • CWE-287 Improper Authentication

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.