CVE-2021-32802
9.3 · CRITICALOverview
CVE-2021-32802 is a critical-severity vulnerability affecting nextcloud nextcloud_server. It was published on September 7, 2021 and has a CVSS 3.1 base score of 9.3 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.3, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Nextcloud server is an open source, self hosted personal cloud. Nextcloud supports rendering image previews for user provided file content. For some image types, the Nextcloud server was invoking a third-party library that wasn't suited for untrusted user-supplied content. There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system. The risk depends on your system configuration and the installed library version. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. These versions do not use this library anymore. As a workaround users may disable previews by setting `enable_previews` to `false` in `config.php`.
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 | >= 0, < 20.0.12 | Affected |
References
Frequently Asked Questions
What is CVE-2021-32802?
CVE-2021-32802 is a critical-severity vulnerability affecting nextcloud nextcloud_server. It was published on September 7, 2021 and has a CVSS 3.1 base score of 9.3 (CRITICAL).
How severe is CVE-2021-32802?
This vulnerability has a CVSS 3.1 base score of 9.3, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-32802?
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-2021-32802?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-32802 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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