CVE-2018-6553 AppArmor cupsd Sandbox Bypass Due to Use of Hard Links

What is CVE-2018-6553?

CVE-2018-6553 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 10 Aug 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

The CUPS AppArmor profile incorrectly confined the dnssd backend due to use of hard links. A local attacker could possibly use this issue to escape confinement. This flaw affects versions prior to 2.2.7-1ubuntu2.1 in Ubuntu 18.04 LTS, prior to 2.2.4-7ubuntu3.1 in Ubuntu 17.10, prior to 2.1.3-4ubuntu0.5 in Ubuntu 16.04 LTS, and prior to 1.7.2-0ubuntu1.10 in Ubuntu 14.04 LTS.

Which versions are affected by CVE-2018-6553?

It affects 3 products.

Products include Canonical Ubuntu Linux, Cups Cups, Debian Debian Linux.

How do I fix CVE-2018-6553?

Apply the vendor's patch.

Is CVE-2018-6553 being exploited?

There is no known exploitation of CVE-2018-6553 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-6553, GHSA-2f8v-v7q3-8gqv, MINI-jprg-cx62-4gvr, UBUNTU-CVE-2018-6553.