TI-2023-13339 Aliases CVE-2023-28833

Unrestricted filenames for logo or favicon as admin in the theming settings in nextcloud server

LOW 39CWE-22Published 2023-03-30 · Updated 2025-02-11

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-434.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00762 55th percentileScored 2026-11-07

Fix Fixed security-advisories (nextcloud): 24.0.10, 25.0.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
nextcloud	security-advisories	before 24.0.10; 25.0.0 to before 25.0.4	24.0.10, 25.0.4	Patch available	CNA

security-advisories Vendornextcloud Affected before 24.0.10; 25.0.0 to before 25.0.4 Fixed in 24.0.10, 25.0.4 Patch available CNA

CPE configurations NVD · 5

CPE	Versions	Role	Vendor
cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*	23.0.0 to before 23.0.14	Vulnerable	nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*	24.0.0 to before 24.0.10	Vulnerable	nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*	24.0.0 to before 24.0.10	Vulnerable	nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*	25.0.0 to before 25.0.4	Vulnerable	nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*	25.0.0 to before 25.0.4	Vulnerable	nextcloud

cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 23.0.0 to before 23.0.14 Vulnerable ·nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 24.0.0 to before 24.0.10 Vulnerable ·nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 24.0.0 to before 24.0.10 Vulnerable ·nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 25.0.0 to before 25.0.4 Vulnerable ·nextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 25.0.0 to before 25.0.4 Vulnerable ·nextcloud

Remediation

Fix · CNA security-advisories (nextcloud) Fixed in 24.0.10, 25.0.4

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2023-28833

References

Patch 1

https://github.com/nextcloud/server/pull/36095

Advisory 1

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-ch7f-px7m-hg25

TI-2023-20855 Users can delete external storage mount points CVSS 3.1HIGH 7.7
TI-2023-11091 Nextcloud download permissions can be changed by resharer CVSS 3.1HIGH 7.5
TI-2023-10624 Nextcloud Server vulnerable to SSRF via filter bypass due to lax checking on IPs CVSS 3.1MEDIUM 5.3
TI-2025-37238 Cross-site scripting in Nextcloud CVSS 3.1MEDIUM 6.4
TI-2023-11086 nextcloud vulnerable to Uncontrolled Resource Consumption CVSS 3.1MEDIUM 6.5
TI-2022-18738 Exception logging in Sharepoint app reveals clear-text connection details CVSS 3.1MEDIUM 6.5

See all 188 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences