In MISP, the event synchronization process contained a logic error in the preparation of event reports for remote push. The filtering of non-exportable tags was applied only once after the iteration over all reports, rather than to each individual report.
As a result:
– All reports except the last one in the set were pushed to the remote MISP instance with their non-exportable tags intact, effectively disclosing restricted tag information to the receiving instance.
– When the last report in the set was withheld (empty), a null report was pushed, causing the remote instance to fail saving the event.
This issue affects any MISP instance configured to push events with multiple reports to a remote server via synchronization.
Affected: <2.5.48.
