CVE-2023-28833

Name: CVE-2023-28833
Creator: NVD / NIST
Published: 2023-03-30T19:15:06.943+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.76%

Last modified Jun 17, 2026

CVE-2023-28833 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Nextcloud server is an open source home cloud implementation. In affected versions admins of a server were able to upload a logo or a favicon and to provided a file name which was not restricted and could overwrite files in the appdata directory. EPSS estimates a 0.76% chance of exploitation in the next 30 days.

Description

Nextcloud server is an open source home cloud implementation. In affected versions admins of a server were able to upload a logo or a favicon and to provided a file name which was not restricted and could overwrite files in the appdata directory. Administrators may have access to overwrite these files by other means but this method could be exploited by tricking an admin into uploading a maliciously named file. It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. Users unable to upgrade should avoid ingesting logo files from untrusted sources.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.76%

50.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Nextcloud Server	>= 23.0.0, < 23.0.14
Nextcloud	Nextcloud Server	>= 24.0.0, < 24.0.10
Nextcloud	Nextcloud Server	>= 25.0.0, < 25.0.4

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-ch7f-px7m-hg25Vendor Advisory
https://github.com/nextcloud/server/pull/36095Issue Tracking, Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-ch7f-px7m-hg25Vendor Advisory
https://github.com/nextcloud/server/pull/36095Issue Tracking, Patch

Timeline

Published: Mar 30, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-28833?

How severe is CVE-2023-28833?

CVE-2023-28833 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.76% probability of exploitation in the next 30 days.

How do I fix CVE-2023-28833?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-28833?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST