============================================================================ Ubuntu Security Notice USN-2855-2 February 16, 2016 samba regression ============================================================================ A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 15.10 - Ubuntu 14.04 LTS - Ubuntu 12.04 LTS Summary: USN-2855-1 introduced a regression in Samba. Software Description: - samba: SMB/CIFS file, print, and login server for Unix Details: USN-2855-1 fixed vulnerabilities in Samba. The upstream fix for CVE-2015-5252 introduced a regression in certain specific environments. This update fixes the problem. Original advisory details: Thilo Uttendorfer discovered that the Samba LDAP server incorrectly handled certain packets. A remote attacker could use this issue to cause the LDAP server to stop responding, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-3223) Jan Kasprzak discovered that Samba incorrectly handled certain symlinks. A remote attacker could use this issue to access files outside the exported share path. (CVE-2015-5252) Stefan Metzmacher discovered that Samba did not enforce signing when creating encrypted connections. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. (CVE-2015-5296) It was discovered that Samba incorrectly performed access control when using the VFS shadow_copy2 module. A remote attacker could use this issue to access snapshots, contrary to intended permissions. (CVE-2015-5299) Douglas Bagnall discovered that Samba incorrectly handled certain string lengths. A remote attacker could use this issue to possibly access sensitive information. (CVE-2015-5330) It was discovered that the Samba LDAP server incorrectly handled certain packets. A remote attacker could use this issue to cause the LDAP server to stop responding, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-7540) Andrew Bartlett discovered that Samba incorrectly checked administrative privileges during creation of machine accounts. A remote attacker could possibly use this issue to bypass intended access restrictions in certain environments. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-8467) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 15.10: samba 2:4.1.17+dfsg-4ubuntu3.2 Ubuntu 14.04 LTS: samba 2:4.1.6+dfsg-1ubuntu2.14.04.12 Ubuntu 12.04 LTS: samba 2:3.6.3-2ubuntu2.14 In general, a standard system update will make all the necessary changes. References: http://www.ubuntu.com/usn/usn-2855-2 http://www.ubuntu.com/usn/usn-2855-1 https://launchpad.net/bugs/1545750 Package Information: https://launchpad.net/ubuntu/+source/samba/2:4.1.17+dfsg-4ubuntu3.2 https://launchpad.net/ubuntu/+source/samba/2:4.1.6+dfsg-1ubuntu2.14.04.12 https://launchpad.net/ubuntu/+source/samba/2:3.6.3-2ubuntu2.14