Cyber Resilience

CVE-2022-39335

Medium

Published: 26 May 2023

Published
26 May 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0014 33.5th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2022-39335 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Matrix Synapse. Its CVSS base score is 5.0 (Medium).

Operationally, ranked at the 33.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix Federation API allows remote homeservers to request the authorization events in a room. This is necessary so that a homeserver receiving some events can validate…

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that those events are legitimate and permitted in their room. However, in versions of Synapse up to and including 1.68.0, a Synapse homeserver answering a query for authorization events does not sufficiently check that the requesting server should be able to access them. The issue was patched in Synapse 1.69.0. Homeserver administrators are advised to upgrade.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

matrix
synapse
≤ 1.69.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-862 CWE-200

Requiring attribute association with information prevents authorization from being performed without necessary security or privacy context.

addresses: CWE-862 CWE-200

Mandates authorization checks before permitting access or data processing via external systems.

addresses: CWE-862 CWE-200

The control provides a mechanism for authorized users to determine authorization matches, preventing sharing without proper authorization verification.

addresses: CWE-200 CWE-862

Session auditing enables detection of unauthorized exposure or access to sensitive information during user activities.

addresses: CWE-200 CWE-862

Sanitizing equipment to remove specified information before off-site maintenance prevents exposure of sensitive information to unauthorized actors such as external maintenance personnel.

addresses: CWE-200 CWE-862

Requiring detailed, requestable records of every PII disclosure directly aids detection of unauthorized exposures of sensitive information.

addresses: CWE-862 CWE-200

Ensures missing authorization mechanisms for critical data functions are identified and remediated via policy.

addresses: CWE-200 CWE-862

Annual reviews and proposal scrutiny detect and block matching programs that would expose sensitive data to unauthorized recipients or systems.

References