Security vulnerability: Samba directory traversal CVE-2021-43566

This document (000020571) is provided subject to the disclaimer at the end of this document.

Environment

For a comprehensive list of affected products and package versions, please visit the SUSE CVE announcement:
https://www.suse.com/security/cve/CVE-2021-43566.html

Situation

Directory traversal vulnerabilities in Samba were identified when using SMB1 or with the share also exported via NFS, might allow remote attackers to create directories on the file server outside of the exported shared area.

Resolution

SUSE will provide fixes samba 4.15.4 updates for SUSE Linux Enterprise 12 SP5 and 15 SP3 and later versions, but currently does not plan this for older Service Packs due to complexity of the backport.

For older service packs please apply the mitigations.

Status

Security Alert

Additional Information

Workaround:

A mitigation is to disable SMB1 (already default disabled in Samba 4.11 and newer), or if SMB1 is required for compatibility reasons disable the UNIX extensions by setting:

unix extensions = no

in the [global] section of /etc/samba/smb.conf and restarting Samba
after the change.

Disclaimer

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