Vulnerability · Published Aug 10, 2023 · Assigned by GitHub_M

CVE-2023-39959Existence of calendars and address books can be checked by unauthenticated users

Low 3.5

In plain English

A low-severity improper access control in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).

Severity (CVSS 3.1)3.5Low

Exploit odds (30 days)0.6%top 50.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 products (as reported)

Vendor	Product	Versions
nextcloud	security-advisories	>= 25.0.0, < 25.0.9>= 26.0.0, < 26.0.4>= 27.0.0, < 27.0.1

Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g97r-8ffm-hfpj x_refsource_CONFIRM
https://github.com/nextcloud/server/pull/38747 x_refsource_MISC
https://hackerone.com/reports/1832126 x_refsource_MISC