4.9 - USN-3713-1

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS - Ubuntu 17.10 - Ubuntu 16.04 LTS - Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in CUPS.

Software Description: - cups: Common UNIX Printing System(tm)

Details:

It was discovered that CUPS incorrectly handled certain print jobs with invalid usernames. A remote attacker could possibly use this issue to cause CUPS to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 17.10 and Ubuntu 18.04 LTS. (CVE-2017-18248)

Dan Bastone discovered that the CUPS dnssd backend incorrectly handled certain environment variables. A local attacker could possibly use this issue to escalate privileges. (CVE-2018-4180)

Eric Rafaloff and John Dunlap discovered that CUPS incorrectly handled certain include directives. A local attacker could possibly use this issue to read arbitrary files. (CVE-2018-4181)

Dan Bastone discovered that the CUPS AppArmor profile incorrectly confined the dnssd backend. A local attacker could possibly use this issue to escape confinement. (CVE-2018-6553)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04 LTS:
cups 2.2.7-1ubuntu2.1

Ubuntu 17.10:
cups 2.2.4-7ubuntu3.1

Ubuntu 16.04 LTS:
cups 2.1.3-4ubuntu0.5

Ubuntu 14.04 LTS:
cups 1.7.2-0ubuntu1.10

In general, a standard system update will make all the necessary changes.

References:
https://usn.ubuntu.com/usn/usn-3713-1
CVE-2017-18248, CVE-2018-4180, CVE-2018-4181, CVE-2018-6553

Package Information:
https://launchpad.net/ubuntu/+source/cups/2.2.7-1ubuntu2.1
https://launchpad.net/ubuntu/+source/cups/2.2.4-7ubuntu3.1
https://launchpad.net/ubuntu/+source/cups/2.1.3-4ubuntu0.5
https://launchpad.net/ubuntu/+source/cups/1.7.2-0ubuntu1.10