ASA-2019-00620 – Samba: Client code can return filenames containing path separators


Allele Security Alert

ASA-2019-00620

Identifier(s)

ASA-2019-00620, CVE-2019-10218

Title

Client code can return filenames containing path separators

Vendor(s)

The Samba Project

Product(s)

Samba

Affected version(s)

Samba versions before 4.11.2
Samba versions before 4.10.10
Samba versions before 4.9.15

Fixed version(s)

Samba version 4.11.2
Samba version 4.10.10
Samba version 4.9.15

Proof of concept

Unknown

Description

Samba client code (libsmbclient) returns server-supplied filenames to calling code without checking for pathname separators (such as “/” or “../”) in the server returned names.

A malicious server can craft a pathname containing separators and return this to client code, causing the client to use this access local pathnames for reading or writing instead of SMB network pathnames.

This access is done using the local privileges of the client.

This attack can be achieved using any of SMB1/2/3 as it is not reliant on any specific SMB protocol version.

Technical details

Unknown

Credits

Michael Hanselmann

Reference(s)

Samba – Security Updates and Information
https://www.samba.org/samba/history/security.html

Client code can return filenames containing path separators
https://www.samba.org/samba/security/CVE-2019-10218.html

CVE-2019-10218
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-10218

CVE-2019-10218
https://nvd.nist.gov/vuln/detail/CVE-2019-10218

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Last modified: November 5, 2019

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