CVE-2023-39959: Existence of calendars and address books can be checked by unauthenticated users
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.9, 26.0.4, and 27.0.1, unauthenticated users could send a DAV request which reveals whether a calendar or an address book with the given identifier exists for the victim. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2023-39959?
CVE-2023-39959 is a vulnerability in Nextcloud Server that allows unauthenticated users to reveal whether a calendar or address book with a specific identifier exists.
What is the severity of CVE-2023-39959?
The severity of CVE-2023-39959 is medium with a CVSS score of 5.3.
Which versions of Nextcloud Server are affected by CVE-2023-39959?
Nextcloud Server versions 25.0.0 to 25.0.9, 26.0.0 to 26.0.4, and 27.0.0 are affected by CVE-2023-39959.
How can unauthenticated users exploit CVE-2023-39959?
Unauthenticated users can exploit CVE-2023-39959 by sending a DAV request to determine the existence of a calendar or address book.
Are there any fixes available for CVE-2023-39959?
Yes, fixes for CVE-2023-39959 are available in versions 25.0.9, 26.0.4, and 27.0.1 of Nextcloud Server.