First published: Tue Oct 31 2023(Updated: )
### Impact Cached device information of remote users can be queried from Synapse. This can be used to enumerate the remote users known to a homeserver. ### Patches System administrators are encouraged to upgrade to Synapse 1.95.1 as soon as possible. ### Workarounds The `federation_domain_whitelist` can be used to limit federation traffic with a homeserver.
Credit: security-advisories@github.com security-advisories@github.com
Affected Software | Affected Version | How to fix |
---|---|---|
pip/matrix-synapse | <1.95.1 | 1.95.1 |
Matrix Synapse | <1.95.1 | |
Fedoraproject Fedora | =38 | |
Fedoraproject Fedora | =39 | |
<1.95.1 | ||
=38 | ||
=39 |
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The vulnerability ID for this Synapse vulnerability is CVE-2023-43796.
The title of this Synapse vulnerability is 'Synapse vulnerable to leak of remote user device information'.
The severity of CVE-2023-43796 is medium with a CVSS v3.1 score of 5.3.
An attacker can exploit this vulnerability by querying the cached device information of remote users from Synapse to enumerate the remote users known to a homeserver.
System administrators should upgrade to Synapse 1.95.1 or 1.96.0 to fix this vulnerability.