Bug 1309992 (CVE-2015-7560) - CVE-2015-7560 samba: Incorrect ACL get/set allowed on symlink path
Summary: CVE-2015-7560 samba: Incorrect ACL get/set allowed on symlink path
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2015-7560
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1314667 1314668 1314669 1314670 1314671 1314672 1314673 1314674 1315942
Blocks: 1309971
TreeView+ depends on / blocked
 
Reported: 2016-02-19 07:27 UTC by Huzaifa S. Sidhpurwala
Modified: 2019-09-29 13:44 UTC (History)
14 users (show)

Fixed In Version: samba 4.4.0rc4, samba 4.3.6, samba 4.2.9, samba 4.1.23
Doc Type: Bug Fix
Doc Text:
A flaw was found in the way Samba handled ACLs on symbolic links. An authenticated user could use this flaw to gain access to an arbitrary file or directory by overwriting its ACL.
Clone Of:
Environment:
Last Closed: 2016-03-24 02:50:01 UTC


Attachments (Terms of Use)


Links
System ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2016:0447 normal SHIPPED_LIVE Moderate: samba security and bug fix update 2016-03-15 16:30:59 UTC
Red Hat Product Errata RHSA-2016:0448 normal SHIPPED_LIVE Moderate: samba security update 2016-03-15 17:18:30 UTC
Red Hat Product Errata RHSA-2016:0449 normal SHIPPED_LIVE Moderate: samba4 security update 2016-03-15 16:30:43 UTC
Samba Project 11648 None None None 2016-03-08 11:35:10 UTC

Description Huzaifa S. Sidhpurwala 2016-02-19 07:27:25 UTC
As per upstream security advisory:

All versions of Samba from 3.2.0 to 4.3.3 inclusive are vulnerable to a malicious client overwriting the ownership of ACLs using symlinks.

An authenticated malicious client can use SMB1 UNIX extensions to create a symlink to a file or directory, and then use non-UNIX SMB1 calls to overwrite the contents of the ACL on the file or directory linked to.

Comment 1 Andreas Schneider 2016-02-26 08:39:46 UTC
Workaround
==========

Add the parameter:

unix extensions = no

to the [global] section of your smb.conf and restart smbd.

Alternatively, prohibit the use of SMB1 by setting the parameter:

server min protocol = SMB2

to the [global] section of your smb.conf and restart smbd.

Comment 5 Siddharth Sharma 2016-03-09 04:28:26 UTC
Created samba tracking bugs for this issue:

Affects: fedora-all [bug 1315942]

Comment 6 Huzaifa S. Sidhpurwala 2016-03-09 04:37:04 UTC
External References:

https://www.samba.org/samba/security/CVE-2015-7560.html

Comment 7 Siddharth Sharma 2016-03-09 09:59:30 UTC
Acknowledgment:

Name: the Samba project
Upstream: Jeremy Allison (Google), the Samba team

Comment 13 errata-xmlrpc 2016-03-15 12:31:14 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2016:0449 https://rhn.redhat.com/errata/RHSA-2016-0449.html

Comment 14 errata-xmlrpc 2016-03-15 12:31:29 UTC
This issue has been addressed in the following products:

  Red Hat Gluster Storage 3.1 for RHEL 7
  Red Hat Gluster Storage 3.1 for RHEL 6

Via RHSA-2016:0447 https://rhn.redhat.com/errata/RHSA-2016-0447.html

Comment 15 errata-xmlrpc 2016-03-15 13:19:01 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2016:0448 https://rhn.redhat.com/errata/RHSA-2016-0448.html


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