CVE-2020-11933: local snapd exploit through cloud-init

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-07-29 · updated 2026-06-17
Weakness: CWE-264

Description

cloud-init as managed by snapd on Ubuntu Core 16 and Ubuntu Core 18 devices was run without restrictions on every boot, which a physical attacker could exploit by crafting cloud-init user-data/meta-data via external media to perform arbitrary changes on the device to bypass intended security mechanisms such as full disk encryption. This issue did not affect traditional Ubuntu systems. Fixed in snapd version 2.45.2, revision 8539 and core version 2.45.2, revision 9659.

Affected products

Canonical Ltd. snapd: before 2.45.2 — fixed in 2.45.2
Canonical Ubuntu Linux: 16.04, 18.04, 19.10, 20.04

How to fix

Upgrade to a fixed version: Canonical Ltd. snapd 2.45.2. Check the vendor advisory for mitigations.

References

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