# CVE-2021-4120: snapd: snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the abil...

CVE-2021-4120 is fixed in 9 products on 1 platform, first by golang-github-snapcore-snapd-dev 2.54.3+18.04, released February 17, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-4120
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0044
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 17, 2022

## Description

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

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | golang-github-snapcore-snapd-dev Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [golang-github-snapcore-snapd-dev 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-golang-github-snapcore-snapd-dev-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | golang-github-snapcore-snapd-dev Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [golang-github-snapcore-snapd-dev 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-golang-github-snapcore-snapd-dev-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | golang-github-ubuntu-core-snappy-dev Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [golang-github-ubuntu-core-snappy-dev 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-golang-github-ubuntu-core-snappy-dev-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | golang-github-ubuntu-core-snappy-dev Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [golang-github-ubuntu-core-snappy-dev 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-golang-github-ubuntu-core-snappy-dev-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | snap-confine Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [snap-confine 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-snap-confine-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | snap-confine Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [snap-confine 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-snap-confine-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | snapd Debian 12.15 (bookworm) | 2.54.3-1 | [DEBIAN-CVE-2021-4120](https://patchblox.com/security/data/fix/linux/debian-cve-2021-4120.md) | Feb 17, 2022 |
| Linux | snapd Debian 13.5 (trixie) | 2.54.3-1 | [DEBIAN-CVE-2021-4120](https://patchblox.com/security/data/fix/linux/debian-cve-2021-4120.md) | Feb 17, 2022 |
| Linux | snapd Debian 14 | 2.54.3-1 | [DEBIAN-CVE-2021-4120](https://patchblox.com/security/data/fix/linux/debian-cve-2021-4120.md) | Feb 17, 2022 |
| Linux | snapd Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [snapd 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-snapd-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | snapd Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [snapd 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-snapd-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | snapd-xdg-open Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [snapd-xdg-open 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-snapd-xdg-open-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | snapd-xdg-open Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [snapd-xdg-open 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-snapd-xdg-open-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | ubuntu-core-launcher Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [ubuntu-core-launcher 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ubuntu-core-launcher-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | ubuntu-core-launcher Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [ubuntu-core-launcher 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ubuntu-core-launcher-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | ubuntu-core-snapd-units Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [ubuntu-core-snapd-units 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ubuntu-core-snapd-units-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | ubuntu-core-snapd-units Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [ubuntu-core-snapd-units 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ubuntu-core-snapd-units-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | ubuntu-snappy Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [ubuntu-snappy 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ubuntu-snappy-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | ubuntu-snappy Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [ubuntu-snappy 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ubuntu-snappy-2.54.3-20.04.1.md) | Feb 17, 2022 |
| Linux | ubuntu-snappy-cli Ubuntu 18.04.6 LTS (bionic) | 2.54.3+18.04 | [ubuntu-snappy-cli 2.54.3+18.04](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ubuntu-snappy-cli-2.54.3-18.04.md) | Feb 17, 2022 |
| Linux | ubuntu-snappy-cli Ubuntu 20.04 LTS (focal) | 2.54.3+20.04.1 | [ubuntu-snappy-cli 2.54.3+20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ubuntu-snappy-cli-2.54.3-20.04.1.md) | Feb 17, 2022 |

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