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6 <title>Samba - Security Announcement Archive</title>
11 <H2>CVE-2019-10218.html:</H2>
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16 == Subject: Client code can return filenames containing
19 == CVE ID#: CVE-2019-10218
21 == Versions: All versions of Samba.
23 == Summary: Malicious servers can cause Samba client
24 code to return filenames containing path
25 separators to calling code.
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32 Samba client code (libsmbclient) returns server-supplied filenames to
33 calling code without checking for pathname separators (such as "/" or
34 "../") in the server returned names.
36 A malicious server can craft a pathname containing separators and
37 return this to client code, causing the client to use this access local
38 pathnames for reading or writing instead of SMB network pathnames.
40 This access is done using the local privileges of the client.
42 This attack can be achieved using any of SMB1/2/3 as it is not reliant
43 on any specific SMB protocol version.
45 Specifically, samba client tools like smbget and smbclient's mget use
46 the server supplied 'final' name component as a local name when
47 obtaining multiple files. While the design of these tools is that
48 server can always choose the file names, this vulnerability is that it
49 allows a remote server to create local files outside the current
52 Users of the libsmbclient library external to Samba may also be
53 vulnerable if they use server returned filenames without adequate
54 checking and pass them to functions that do local filesystem access.
56 Note that the Gnome GVFS client library is not believed to be
57 vulnerable, as it always passes server-returned pathnames back to the
58 SMB share they were returned from. Such malformed pathnames are then
59 rejected by the server.
65 Patches addressing both these issues have been posted to:
67 http://www.samba.org/samba/security/
69 Additionally, Samba 4.11.2, 4.10.10 and 4.9.15 have been issued as
70 security releases to correct the defect. Samba administrators are
71 advised to upgrade to these releases or apply the patch as soon as
78 CVSSv3: AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N (5.3)
90 Originally reported by Michael Hanselmann.
92 Patches provided by Jeremy Allison of the Samba Team and Google.
94 Advisory by Jeremy Allison of the Samba Team and Google and Andrew
95 Bartlett of the Samba Team and Catalyst.
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98 == Our Code, Our Bugs, Our Responsibility.
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