2.7 Low
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
4 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:S/C:P/I:N/A:N
0.001 Low
EPSS
Percentile
25.0%
So with the default settings Nextcloud still sends requests to the lookup server if users update their profile. Even if none of the fields are set to ‘published’.
I must admit this is somewhat of a surprise as there is no reason for this. As long as the visibility of none of the fields change and none of them are published.
The background job is inserted in the function
https://github.com/nextcloud/server/blob/master/apps/lookup_server_connector/lib/UpdateLookupServer.php#L62
And the DELETE that is executed
https://github.com/nextcloud/server/blob/master/apps/lookup_server_connector/lib/BackgroundJobs/RetryJob.php#L156
Looking at the lookup server code it seems to actually do the delete. Still users of course can’t verify what is running there. So we have to assume the worst case scenario where the lookup server has a list of a significant portion of all the nextcloud users out there.
The nextcloud server is still sharing the federated cloud id of every user to the lookupserver. Unless an admin explicitly disables the lookupserver.
Even if non of the fields are set to published.
2.7 Low
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
4 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:S/C:P/I:N/A:N
0.001 Low
EPSS
Percentile
25.0%