CVE-2023-48239
8.5 · HIGHOverview
CVE-2023-48239 is a high-severity vulnerability affecting nextcloud nextcloud_server. It was published on November 21, 2023 and has a CVSS 3.1 base score of 8.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Server and starting in version 20.0.0 and prior to versions 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Enterprise Server, a malicious user could update any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud Server 25.0.13, 26.0.8, and 27.1.3 and Nextcloud Enterprise Server is upgraded to 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 contain a patch for this issue. As a workaround, disable app files_external. This workaround also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.
Remediation
Check the references section for vendor advisories and patches from nextcloud. Update nextcloud_server to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| nextcloud | nextcloud_server | >= 20.0.0, < 20.0.14.16 | Affected |
References
Frequently Asked Questions
What is CVE-2023-48239?
CVE-2023-48239 is a high-severity vulnerability affecting nextcloud nextcloud_server. It was published on November 21, 2023 and has a CVSS 3.1 base score of 8.5 (HIGH).
How severe is CVE-2023-48239?
This vulnerability has a CVSS 3.1 base score of 8.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2023-48239?
Check the references section for vendor advisories and patches from nextcloud. Update nextcloud_server to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2023-48239?
CyberStrike's AI-powered security agents can automatically detect CVE-2023-48239 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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