snapd could be made to bypass intended access restrictions through snap content interfaces and layout paths
CVE-2021-4120

8.2HIGH

Key Information:

Vendor

Canonical Ltd.

Status
Snapd
Vendor
CVE Published:
17 February 2022

What is CVE-2021-4120?

snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

Affected Version(s)

snapd <= 2.54.2

References

https://ubuntu.com/security/notices/USN-5292-1
x_refsource_MISC
https://bugs.launchpad.net/snapd/+bug/1949368
x_refsource_MISC
http://www.openwall.com/lists/oss-security/2022/02/18/2
mailing-listx_refsource_MLIST

CVSS V3.1

Score:
8.2
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Ian Johnson
.
CVE-2021-4120 : snapd could be made to bypass intended access restrictions through snap content interfaces and layout paths