Description
A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with access to a shared CalDAV calendar to exfiltrate arbitrary files the user has access to when interacting with malicious calendar events.
References3
Metrics
- CVSS 3.1
-
5.7
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 0% percentile: 33 · as of 11 November 2026
- CWE
- CWE-200
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.