CVE intelligence and bounded remediation
CVE-2021-32802 — Nextcloud server is an open source, self hosted personal cloud
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`.
- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Published
- 2021-09-07
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-829
Affected products
- nextcloud / nextcloud_server
Showing 1 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.
Matched remediation archetype
Supply-chain, dependency, build, and update integrity
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace affected packages, source archives, build actions, plugins, installers, and updates from declared source to deployed artifact.
- Confirm provenance, signatures or digests, namespace ownership, lockfile resolution, registry configuration, and build-runner trust boundaries.
- Inventory direct, transitive, vendored, generated, and bundled copies across releases and distribution channels.
Remediate safely
- Move to a maintained trusted artifact or remove the dependency; pin immutable identities and verify provenance and integrity before use.
- Regenerate lockfiles and artifacts in a clean isolated build, minimize build credentials and network access, and produce an updated software bill of materials.
- Require reviewed update policy, protected publishing, and reproducible or independently attestable builds where supported.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.