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Improper Handling of Unexpected Data Type

CVE-2025-66550

Medium
5.7/10

Summary

Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • REQUIRED
  • LOW
  • NONE
  • NONE

CWE-241 - Improper Handling of Unexpected Data Type

The software does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).

References

Advisory Timeline

  • Published