CVE-2019-15621: 
Linux openSUSE vulnerability analysis and mitigation

CVE-2019-15621 is a vulnerability discovered in Nextcloud Server 16.0.1 related to improper permissions preservation. The vulnerability allows sharees to reshare mount points of received shares as public links with write permissions, which could lead to unauthorized access and modifications (OpenSUSE Security, CVE Mitre).

The vulnerability is identified as NC-SA-2020-012 in Nextcloud's security advisory system. It specifically affects the sharing mechanism in Nextcloud Server 16.0.1, where the system fails to properly preserve permission restrictions when users reshare mount points they have received (OpenSUSE Security).

The vulnerability could allow users to escalate their sharing permissions by creating public links with write access to content they should only have read access to, potentially compromising data security and access control mechanisms (OpenSUSE Security).

The vulnerability was addressed in subsequent updates to Nextcloud. Users are advised to upgrade to patched versions. The fix was included in Nextcloud 15.0.14 release and was distributed through various platform-specific updates including SUSE Package Hub and openSUSE Backports (OpenSUSE Security).