MISP contains a defect in its event save workflow that prevents the correlation engine from recalculating correlations when an event's distribution level or sharing group is modified.
When a user edits an existing event and changes its distribution or sharing_group_id, the internal before-save hook stored the incoming (new) data rather than the previously persisted values. As a result, the after-save comparison that determines whether a correlation refresh is needed never detected the change, and stale correlations persisted.
Security impact:
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Stale correlations may continue to expose event data to users in a broader sharing group after the event has been moved to a more restrictive group, resulting in unintended information disclosure.
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Conversely, newly relevant correlations may not appear after a distribution widening, degrading the completeness of threat intelligence sharing.
Preconditions:
Affected versions: <2.5.48
The fix ensures that the before-save hook retrieves the previously persisted distribution and sharing_group_id values from the database for existing events, rather than capturing the incoming (new) data. This allows the after-save logic to correctly detect when these fields have changed and trigger a correlation refresh, ensuring access boundaries on correlated data are enforced promptly.