by Kastro
Paper/Archive/CVE-2021-32802

CVE-2021-32802

nextcloud security-advisories — Preview generation used third-party library not suited for user-generated content in Nextcloud server

EPSS 3%CVSS 9.8
critical.is priorityof 100
47
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 85.4.854 × 2017.1No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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`.

Affected

ProductAffectedFixed inSource
security-advisories< 20.0.12–CNA
security-advisories>= 21.0.0, < 21.0.4–CNA
security-advisories>= 22.0.0, < 22.1.0–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub_M (CNA)9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L

References

refgithub.com/nextcloud/security-advisories/security/advisories/GHSA-m682-v4g9-wrq7refhackerone.com/reports/1261413refdocs.nextcloud.com/server/21/admin_manual/configuration_files/previews_configuration.html#disabling-previewsadvisorysecurity.gentoo.org/glsa/202208-17