Ubuntu Security Notice 3348-1 - It was discovered that Samba incorrectly handled dangling symlinks. A remote attacker could possibly use this issue to cause Samba to hang, resulting in a denial of service. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. In addition, this update fixes a regression introduced by USN-3267-1 that caused Samba to incorrectly handle non-wide symlinks to directories.
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Ubuntu Security Notice USN-3348-1
July 05, 2017
samba vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 17.04
- Ubuntu 16.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
Summary:
Samba could be made to hang if it received specially crafted network
traffic.
Software Description:
- samba: SMB/CIFS file, print, and login server for Unix
Details:
It was discovered that Samba incorrectly handled dangling symlinks. A
remote attacker could possibly use this issue to cause Samba to hang,
resulting in a denial of service. This issue only applied to Ubuntu 14.04
LTS and Ubuntu 16.04 LTS. (CVE-2017-9461)
In addition, this update fixes a regression introduced by USN-3267-1
that caused Samba to incorrectly handle non-wide symlinks to directories.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 17.04:
samba 2:4.5.8+dfsg-0ubuntu0.17.04.3
Ubuntu 16.10:
samba 2:4.4.5+dfsg-2ubuntu5.7
Ubuntu 16.04 LTS:
samba 2:4.3.11+dfsg-0ubuntu0.16.04.8
Ubuntu 14.04 LTS:
samba 2:4.3.11+dfsg-0ubuntu0.14.04.9
In general, a standard system update will make all the necessary changes.
References:
https://www.ubuntu.com/usn/usn-3348-1
CVE-2017-9461
Package Information:
https://launchpad.net/ubuntu/+source/samba/2:4.5.8+dfsg-0ubuntu0.17.04.3
https://launchpad.net/ubuntu/+source/samba/2:4.4.5+dfsg-2ubuntu5.7
https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.16.04.8
https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.14.04.9