Headline
GHSA-3h7q-rfh9-xm4v: Synapse V2 state resolution weakness allows Denial of Service (DoS)
Impact
A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in how the auth chain cover index is calculated. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service.
Servers in private federations, or those that do not federate, are not affected.
Patches
Server administrators should upgrade to 1.105.1 or later.
Workarounds
One can:
- ban the malicious users or ACL block servers from the rooms; and/or
- leave the room and purge the room using the admin API
For more information
If you have any questions or comments about this advisory, please email us at security AT element.io.
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- GitHub Advisory Database
- GitHub Reviewed
- CVE-2024-31208
Synapse V2 state resolution weakness allows Denial of Service (DoS)
Moderate severity GitHub Reviewed Published Apr 23, 2024 in element-hq/synapse • Updated Apr 23, 2024
Package
pip matrix-synapse (pip)
Affected versions
< 1.105.1
Description
Impact
A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in how the auth chain cover index is calculated. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service.
Servers in private federations, or those that do not federate, are not affected.
Patches
Server administrators should upgrade to 1.105.1 or later.
Workarounds
One can:
- ban the malicious users or ACL block servers from the rooms; and/or
- leave the room and purge the room using the admin API
For more information
If you have any questions or comments about this advisory, please email us at security AT element.io.
References
- GHSA-3h7q-rfh9-xm4v
- https://nvd.nist.gov/vuln/detail/CVE-2024-31208
- element-hq/synapse@55b0aa8
- https://github.com/element-hq/synapse/releases/tag/v1.105.1
Published to the GitHub Advisory Database
Apr 23, 2024
Last updated
Apr 23, 2024