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Vulnerability · Published Jul 29, 2020 · Assigned by canonical

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

Medium 5.9

In plain English

A medium-severity security flaw in snapd from Canonical. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)0.4%top 69.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12snapd2.45.2-1DEBIAN-CVE-2020-11934
Debian:13snapd2.45.2-1DEBIAN-CVE-2020-11934
Debian:14snapd2.45.2-1DEBIAN-CVE-2020-11934

Affected products (as reported)

VendorProductVersions
Canonical snapd 2.45.1 – before 2.45.1ubuntu0.2

References