# CVE-2021-44731: snapd: A race condition existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap

CVE-2021-44731 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-2021-44731
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0095
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 17, 2022

## Description

A race condition existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap. This could allow a local attacker to gain root privileges by bind-mounting their own contents inside the snap's private mount namespace and causing snap-confine to execute arbitrary code and hence gain privilege escalation. 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-2021-44731](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44731.md) | Feb 17, 2022 |
| Linux | snapd Debian 13.5 (trixie) | 2.54.3-1 | [DEBIAN-CVE-2021-44731](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44731.md) | Feb 17, 2022 |
| Linux | snapd Debian 14 | 2.54.3-1 | [DEBIAN-CVE-2021-44731](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44731.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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