Home/CVE/Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forg
CVE

CVE-2023-42453

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forg

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read.

This could be confusing as clients will show the event as read by the user, even if they are not in the room. This issue has been patched in version 1.93.0. Users are advised to upgrade.

There are no known workarounds for this issue.

LOW · CVSS 3.1 EPSS 0.00132
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0

Weakness Classification

Affected Products & Versions

2
matrix synapse>= 1.34.0 and < 1.93.0

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI matrix-synapse MODERATE fixed in 1.93.0

Scoring & Timeline

3.1
LOW · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD27 Sep 2023 · 03:19 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

Vendor Advisories

2
suse-csafopenSUSE-SU-2024:13270-1
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