CVE-2018-6954 Path traversal in n/a

What is CVE-2018-6954?

CVE-2018-6954 is a high-severity path traversal vulnerability in Canonical Ubuntu Linux, published on 13 Feb 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path components, which allows local users to obtain ownership of arbitrary files via vectors involving creation of a directory and a file under that directory, and later replacing that directory with a symlink. This occurs even if the fs.protected_symlinks sysctl is turned on.

Weakness: CWE-59

Which versions are affected by CVE-2018-6954?

It affects 3 products.

Products include Canonical Ubuntu Linux, Opensuse Leap, Systemd Project Systemd.

How do I fix CVE-2018-6954?

Apply the vendor's patch.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2018-6954 being exploited?

There is no known exploitation of CVE-2018-6954 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-2018-6954, GHSA-fgm4-rh7c-g9fg, UBUNTU-CVE-2018-6954, USN-3816-2.