CVE-2020-11934 Sandbox escape vulnerability via snapctl user-open (xdg-open)

What is CVE-2020-11934?

CVE-2020-11934 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 29 Jul 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

It was discovered that snapctl user-open allowed altering the $XDG_DATA_DIRS environment variable when calling the system xdg-open. OpenURL() in usersession/userd/launcher.go would alter $XDG_DATA_DIRS to append a path to a directory controlled by the calling snap. A malicious snap could exploit this to bypass intended access restrictions to control how the host system xdg-open script opens the URL and, for example, execute a script shipped with the snap without confinement. This issue did not affect Ubuntu Core systems. Fixed in snapd versions 2.45.1ubuntu0.2, 2.45.1+18.04.2 and 2.45.1+20.04.2.

Weakness: CWE-668

Which versions are affected by CVE-2020-11934?

It affects 1 product.

Products include Canonical Ubuntu Linux.

How do I fix CVE-2020-11934?

Apply the vendor's patch.

Is CVE-2020-11934 being exploited?

There is no known exploitation of CVE-2020-11934 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-2020-11934, GHSA-8cwp-mjww-pqc2, UBUNTU-CVE-2020-11934, USN-4424-1.