CVE-2023-25579: Directory traversal in Nextcloud server

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-02-22 · updated 2026-06-17
Weakness: CWE-22

Description

Nextcloud server is a self hosted home cloud product. In affected versions the `OC\Files\Node\Folder::getFullPath()` function was validating and normalizing the string in the wrong order. The function is used in the `newFile()` and `newFolder()` items, which may allow to creation of paths outside of ones own space and overwriting data from other users with crafted paths. This issue has been addressed in versions 25.0.2, 24.0.8, and 23.0.12. Users are advised to upgrade. There are no known workarounds for this issue.

Affected products

Nextcloud Server: before 23.0.12; from 20.0.0 before 20.0.14; from 21.0.0 before 21.0.9; from 22.2.0 before 22.2.10; from 23.0.0 before 23.0.12; from 24.0.0 before 24.0.8 — fixed in 20.0.14, 21.0.9, 22.2.10, 23.0.12, 24.0.8, 25.0.2

How to fix

Upgrade to a fixed version: Nextcloud Server 20.0.14, 21.0.9, 22.2.10, 23.0.12. Check the vendor advisory for mitigations.

References

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