==================================================================== == Subject: Server memory information leak over SMB1 == == CVE ID#: CVE-2017-12163 == == Versions: All versions of Samba. == == Summary: Client with write access to a share can cause == server memory contents to be written into a file == or printer. == ==================================================================== =========== Description =========== All versions of Samba are vulnerable to a server memory information leak bug over SMB1 if a client can write data to a share. Some SMB1 write requests were not correctly range checked to ensure the client had sent enough data to fulfill the write, allowing server memory contents to be written into the file (or printer) instead of client supplied data. The client cannot control the area of the server memory that is written to the file (or printer). ================== Patch Availability ================== A patch addressing this defect has been posted to http://www.samba.org/samba/security/ Additionally, Samba 4.6.8, 4.5.14 and 4.4.16 have been issued as security releases to correct the defect. Patches against older Samba versions are available at http://samba.org/samba/patches/. Samba vendors and administrators running affected versions are advised to upgrade or apply the patch as soon as possible. ========== Workaround ========== As this is an SMB1-only vulnerability, it can be avoided by setting the server to only use SMB2 via adding: server min protocol = SMB2_02 to the [global] section of your smb.conf and restarting smbd.