What happened
Cross-site scripting (XSS) vulnerability in a reachable files_pdfviewer example directory in Nextcloud with versions before 22.2.10.33, 23.0.12.29, 24.0.12.28, 25.0.13.23, 26.0.13.20, 27.1.11.20, 28.0.14.11, 29.0.16.8, 30.0.17, 31.0.10, and 32.0.1 allows attackers to execute arbitrary JavaScript in the context of a user's browser via a crafted PDF file to viewer.html. This issue is related to CVE-2024-4367, but the root cause of this Nextcloud issue is that the product exposes executable example code on a same-origin basis.
Affected versions
Nextcloud: before 22.2.10.33 (custom); 23 through before 23.0.12.29 (custom); 24 through before 24.0.12.28 (custom); 25 through before 25.0.13.23 (custom); 26 through before 26.0.13.20 (custom); 27 through before 27.1.11.20 (custom); 28 through before 28.0.14.11 (custom); 29 through before 29.0.16.8 (custom); 30 through before 30.0.17 (custom); 31 through before 31.0.10 (custom); 32 through before 32.0.1 (custom) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.