Nextcloud Server 25-27 Unauth DAV ID Leak (v25.0.9/26.0.4/27.0.1)
CVE-2023-39959 Published on August 10, 2023
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.
Vulnerability Analysis
CVE-2023-39959 can be exploited with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is an Authorization Vulnerability?
The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CVE-2023-39959 has been classified to as an Authorization vulnerability or weakness.
Products Associated with CVE-2023-39959
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Affected Versions
nextcloud security-advisories:- Version >= 25.0.0, < 25.0.9 is affected.
- Version >= 26.0.0, < 26.0.4 is affected.
- Version >= 27.0.0, < 27.0.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.