Nextcloud Server <24.0.10 Unrestricted Logo Upload Enables File Overwrite
CVE-2023-28833 Published on March 30, 2023
Unrestricted filenames for logo or favicon as admin in the theming settings in nextcloud server
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.
Vulnerability Analysis
CVE-2023-28833 can be exploited with network access, requires user interaction and 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 no impact on confidentiality and integrity, and a small impact on availability.
Weakness Type
What is a Directory traversal Vulnerability?
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CVE-2023-28833 has been classified to as a Directory traversal vulnerability or weakness.
Products Associated with CVE-2023-28833
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Affected Versions
nextcloud security-advisories:- Version < 24.0.10 is affected.
- Version >= 25.0.0, < 25.0.4 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.